I saw THE HOBBIT and I loved it. I'm saying that now because most people I know seem to be really polarized about it, and whether they liked it or not seems to in large part be based on a few very particular expectations. SO MANY SPOILERS AHEAD. You have been warned.
Expectation 1. That this would be an adaptation of the original book only, with no added materials that connect and contextualize it with LOTR (which, with 3 movies, was clearly never going to be the case. Jackson was also up front about this and discussed some of what would be added, so it shouldn't really be a surprise to anyone that it's not just a straight adaptation. I mean, LOTR wasn't, either.)
Expectation 2. A nostalgic and personal attachment to the story that led them to want "their" adaptation be what Jackson would tell, which makes it pretty impossible for Jackson to do much of anything right unless he ignored all of LOTR and what Tolkien actually wanted for the story. And even then, when you start wrapping up personal attachment in something, anyone else's version or interpretation of it will come up lacking.
Now, I'm not going to say anyone should like THE HOBBIT if they don't. We all have subjective preferences and sometimes things just don't click. That's the nature of stories and definitely the nature of adaptations. It's even more true when we're talking about a beloved book that so many people remember fondly from childhood.
That said, I want to explain why I do love it, and why for me personally it hit all the right notes. I don't want it to come across as fanier-than-thou, and I fully acknowledge that I'm the sort of Tolkien nerd who loves all the history, the appendices, the Silmarillion shout outs, and has not viewed THE HOBBIT as a separate entity from LOTR since I was about 8. And, to be frank, as an adult who recently re-read THE HOBBIT...I find it to be a highly flawed narrative with little to no characterization. The last 3rd of the book feels drastically different than the first 2/3rds, a lot of essential material and character motivation is left out until that last third, and it has a weird pace. It has great scenes, like the riddles with Gollum, but that's largely because Tolkien went back in after the first edition and fixed things because he had much more fully fleshed out his world and wanted it to be more integrated. He also established THE HOBBIT was originally Bilbo's recounting of the tale with severe omissions and even some outright lies, especially about The Ring and how he came by it. He only tells Gandalf the truth after some haranguing. You can look it up, Tolkien knew what he was doing. And before anyone argues that he "shouldn't" have wanted to change it...he did. Because he was a world-builder and epic storyteller and he wanted it all to matter. He was something of an obsessive consistency nut. In this case, he was right.
Beyond that, unless you've been reading the 1937 first edition version only, you've never read the THE HOBBIT that's not connected to LOTR. So, whether you personally like it or not, it's been connected to a larger and more "mature" narrative for a long time. And it had events happening concurrently and parallel it, that give it weight it otherwise wouldn't. A weight that the later events and tone of the book, to me, clearly indicate.
I've always thought THE HOBBIT was quite dark even with the quicker pace and levity. As dark as LOTR? No. But then, LOTR isn't as dark as The Silmarillion. The latter makes everything else look like a fun, sunnily lit romp. However, THE HOBBIT is full of things trying to eat our merry band, from trolls to goblins to spiders to a dragon. There's also Thorin's arc, which gets incredibly dark towards the end. There's some really complex stuff going on there, but it's a bit confusing because it has little context. Which the movie, by bringing in elements like the Arkenstone earlier, builds much more consistently. The book just drops that on you out of the blue, in the last act practically. It's a major point of contention between Thorin and Bilbo, Thorin and Gandalf, and nearly leads to a war between elves and dwarves. Thematically, that's not very "light-hearted".
Which brings me to characterization. Look, I love Tolkien. My dad read me THE HOBBIT when I was about 5 or so. And to a degree it's a "kids" book...with darker subject matter than you might grasp at 5, but certainly will later. But as I mentioned earlier, it has issues. A big one is a lack of characterization for even main figures like Bilbo for quite awhile. And that really can't be swept away by saying it's "just a kids story". We all know many kids stories can be (and are) WAY better about that sort of thing. It's really because Tolkien was not yet the writer he became. So regardless of how much we may love it, in comparison to what he later achieved with LOTR and The Silmarillion, it's not even remotely as solid a story or world. The fact that he wanted to fix that later makes absolute sense to me, and the fact that he did some of it via "retcon" shouldn't be nearly so surprising to some fans.
By changing a few things, Jackson gave Bilbo a bit more agency up front (choosing to go on the quest instead of Gandalf basically shoving him out the door, figuring out he should maybe try stalling the trolls until daylight, coming to Thorin's defense). This makes his arc as a character more believable because he does have some of these positive traits already. They just need to be brought out by the circumstances. He starts out fussy, with glimmers of risk-taking and cleverness. Which come up again later in various circumstances (trolls, Gollum, spiders, barrel ride, Smaug, info via thrush to Dale, they all build toward each other). That's how you work a character arc.
Likewise, opening with just how dangerous and deadly Smaug is gives context to what the dwarves lost and shows us just how nutty their quest is. This dragon laid -waste- to them. They could die. In fact, they probably will, because there are 13 of them (and one hobbit) and they're going up against a DRAGON. With that history we now know Thorin feels obligated to make things better for his people and that dwarves might be just a little bit crazy. I mean, in LOTR the only dwarf we get to know is Gimli. THE HOBBIT allows us to find out that they're all a little mad, but also that they -matter- to this world beyond Gimli's lack of running skills and quaffing. I can't help but think that's a good thing. And certainly something Tolkien would have approved of.
This is also the reason I was very happy to see the White Council scene. Mostly because I just want more Galadriel, but also because what happens with the Necromancer is pretty important in explaining why Gandalf basically effs off and lets the dwarves flail around in Mirkwood and deal with a dragon all by themselves. Which otherwise seems pretty weird. At least now we'll know he had a pretty good effing reason to do so, and deal with more of what leads up to LOTR which is the "big" story, like it or not. And in any case, it already exists as film adaptations.
To me, THE HOBBIT is structured not all that dissimilarly to FOTR. It begins with backstory about the dwarves rather than Galadriel recounting Sauron and the Last Alliance. It moves into Bilbo and Frodo on the day of the party, with Bilbo deciding he should maybe write down the REAL story instead of the altered one he clearly told Frodo. Not unlike how he then moved into talking about hobbits and their less than wise or great status in the world. After that it leads into the quest at hand, gives both Thorin and Bilbo solid arcs within this installment, that will lend themselves to their overall arcs. Gandalf gets a bit less there because his arc is for the way long haul, but even he is less sure than he is in FOTR, and obviously way less than when he becomes Gandalf the White.
The reality is, no one should be surprised that Jackson adapted THE HOBBIT this way. He adapted LOTR, he couldn't just ignore that or pretend THE HOBBIT was some separate thing with no context or parallel events. The fact that he took so much time to line them up is actually a testament to how much he values the work, the stories, and Tolkien.
The other thing is, Jackson couldn't make THE HOBBIT after LOTR and not have to consider a myriad of viewers. Those who may not be familiar with any of it, those who may only be familiar with THE HOBBIT, those who have read and watched LOTR and read THE HOBBIT, and those who have only watched LOTR. He gambled on including more context and story because I think that's the way he personally prefers the stories, and because Tolkien provided a great deal of the material, so the amount of "added" stuff isn't actually a stretch. And because that allows it to gel more thoroughly with LOTR. Which is obviously going to work or not work for you. He couldn't have made a film version for "everyone" because there's no such thing. When your'e adapting a work you are making choices and no two people will agree with some, most, or even any. At a certain point you can't worry about that, you have to just go with what you think is best and hope most people will go along for the ride.
The reason I'm not being nitpicky about story changes in THE HOBBIT is because I'd have to go and do that to LOTR. And to be honest, I like the story changes he made in THE HOBBIT. They work for me. They give me more characterization, more history, more context, more cohesion. There's a structured narrative that's building towards an end goal. There are actual personalities to relate to.
I mean, in THE HOBBIT, the troll scene exists pretty much exclusively to get Thorin, Bilbo, and Gandalf elf blades that glow blue. In the book, because Gandalf fixes the problem by throwing his voice, it serves no real narrative or character purpose, other than that Bilbo is a really crap burglar. In the film we see Bilbo being at least slightly clever and Thorin & co get to be brave and then quarrelly dwarves. Gandalf still saves the day, but we get some personality quirks and relationships established. Frankly, that's better use of a scene as storytelling.
I guess, at the end of it, I get that this version of THE HOBBIT may be so different than what some people wanted/expected that it just won't work for them. In my mind it's important to put your expectations aside when you view an adapt, but I don't mean that as a judgment, or to imply anyone who doesn't like the movie is stupid. That would be absurd. Liking something is entirely subjective, and as a hugely nerdy Tolkien fan, I am absolutely aware of my own lack of objectivity. But it's not because I'm just such a huge fan that I can't see flaws. If you get me going I'll tell you every nitpicky issue I have with some ROTK story choices in particular. Or the individual LINE changes that still drive me crazy (Galadriel's line in FOTR at the pool is "Things that are, things that were, and things that yet may be." NOT "things that have not yet come to pass". I will NEVER understand why it was changed to something so unwieldy when the original was simple and poetic).
For me, an adaptation works or does not work based on a bunch of factors. One of them being how closely it retains the "spirit" of the original creators work, even if it deviates hugely in how it shows that. LOTR, for instance, has a LOT of story deviations. Just as many as THE HOBBIT, actually, since a great deal of what's added in this is direct from Tolkien, and quite a bit of what was added or changed in LOTR was not. The results take the characters to more or less the same places narratively, they just take a bit of a deviated path to get there. You can see that "literally" in TTT when Faramir takes Frodo and Sam to Osgiliath and nearly turns them over to his father, something that didn't even come close to happening in the book. Or take the entirety of Denethor where, because they took out him having a Palantir, he becomes just an obnoxious lunatic, not a pathetic and damaged man whose mind has been corrupted by false information. Those are choices Jackson made, and whether I agree with them or not (to note: I agree with the Faramir one, not the Denethor one) the end results were still pretty close to what Tolkien wrote while maintaining the changes they needed to make the film work.
I've seen film adapts that are incredibly different from the source in terms of how the story is told, but equally viable. What's interesting about THE HOBBIT is that it's both true and not-true to the original. The parts that are directly from the novel are, obviously, "true" to it. But they add layer and depth that I personally think it desperately needed to be adapted to film, especially in the area of characterization and actions happening over more than a sentence.. The "added" material, which is somewhat tonally different, doesn't, for me, undermine the "spirit", however...because to do that you have to look at LOTR and what Tolkien was doing with the entirety of the Middle Earth tales he told. It simply doesn't exist as a separate entity, especially because there are already 3 films that established that world. Basically: you can't put the genie back in the bottle. Just because it's not a faithful retelling of the book doesn't make it "bad". It's actually a strong, cohesive narrative. I honestly and truly believe that it would have been way too incongruous and strange not to have given it this level of context.
Simply put: I believe Jackson made THE HOBBIT this way to acknowledge the depth and scope of the world the story exists in, the story it leads up to, and the importance of the story itself. Because it really isn't "just" a kids story or "just" a happy quest. It matters more than that, and I'm happy to see it filmed that way. If the other two are anything like it, I will be a very thrilled fan.