Not really spoilers ahead for The Hobbit movies. Technically the book too, but for something that's been around in the popular consciousness since 1937 I think is less a spoiler than indicating something exists.
First off, it should surprise no one that I really like Tolkien even with all the flaws. He was an English professor and really loved mythology, so I can at least dig his chosen subject matter even if I find the execution sometimes falling rather short. I may not be as incredibly familiar with all of his works as others, but The Hobbit and The Lord of the Rings were part of my childhood in the form of the books and animated films, and to this day it is still something I remember with great fondness. That being said, the film adaptations of Peter Jackson's The Hobbit thus far are, let's just say, giving me complicated feels. On the one hand, they are visually well done, clearly trying to stay faithful to the source material, and are some incredible examples of the film medium. On the other hand, Peter Jackson has made a very bloated and overly complicated adaptation of what is supposed to be a more lighthearted and fun prequel to The Lord of the Rings trilogy. This movie has a lot more pacing problems than the first Hobbit film, which is really saying something.
The original novel was just over 300 pages, so everyone knew Peter Jackson would have to be padding the hell out of the plot to extend the story into three films. The thing is, for pretty much a significant of the movie, I was taken out of the experience by trying to guess what was going to happen next from what I already knew about the story. A lot of scenes that actually happen fairly quickly in the book are drawn out by fancy action scenes. I'm not really against fancy action scenes generally, and I'm sure a lot of internet people have already gushed about the river barrel scene; however, I kept questioning the whole time when it was going to be over because the film was nearly two hours in and we still needed to get to Lake Town and from there to the Lonely Mountain and deal with the dragon Smaug. I kept getting the feeling that we were rushing the main plot, but at the same time taking forever to get there.
Another common point of contention in these movies is all the references to later events in The Lord of the Rings. To that I say that it was quite clear with the first film, The Hobbit: An Unexpected Journey, that Peter Jackson was going to remind us every step of the way that all of these events happen before those of the The Lord of the Rings. Which brings me to what some reviewers have already realized: these films aren't for the general public, they are for the fans. All of the extended scenes, bonus content, and other extra information included with these movies is to bring Tolkien's works to life as best as can be done in an early 21st century Western society, while still subtly reinforcing problematic issues Western culture has dealt with for a very long time. That being said, there are some glaring flaws in the second movie released, The Hobbit: The Desolation of Smaug, that are not entirely related to the same issues as a lot of films that are in the middle of a trilogy. Since this film is only part of the whole story, no matter where it finishes, the action is going to be halted in a bizarre way that will more likely leave audiences angry than eager to continue. At least it did for me. My friend and I were the only ones who screamed in frustration at the rolling of the end credits, and I haven't bothered checking for similar experiences from others. The same frustration happened with Pirates of the Caribbean, Star Wars, and many others too, don't pretend it didn't, I know people out there who had the same issues.
Another thing I didn't realize until it was pointed out to me is that in these film adaptations, Bilbo Baggins isn't really the hero of the story. Yes, he is heroic by virtue of the heroic things he does, but he isn't really the story here. If anything, these films are about Gandalf and Thorin. This situation is best shown by how the first Hobbit film took 40 minutes to even get to Bilbo, and the second movie has to open with about 10 minutes of Gandalf/Thorin flashback before getting to the title and where we left off last time with Bilbo and the gang. Mark my words, the third movie will focus a significant chunk on Thorin Oakenshield and his tragic downfall.
Now in terms of Tolkien's works, many people have already listed some broad issues with the entire body of fiction on Middle Earth. There is the issue of racism, since very few of the human or fantasy races have people of color as main characters, and there are also rather few POC in the backgrounds of crowd shots. There is also the issue of sexism, which Peter Jackson tried to counter by shoehorning in a romantic subplot with an original female character in the form of Tauriel in Desolation of Smaug. I don't really mind the inclusion of an original character, since Peter Jackson has been doing that the whole time with the characters of the dwarves and other minor characters that don't have much role in Tolkien's stories, but are still there. The thing is, with Tauriel, I really like her as a character, but I don't like the romance subplot she was chosen to fulfill in these movies. She is clearly quite competent at her job as a warrior of the Wood Elves, and an aspect of the story I enjoyed a great deal in the theatrical release was her ability to see the big picture of what was happening in Middle Earth at the time. However, I felt a distinct lack of romantic interest from her end in any of the male characters interested in her, but that could definitely be changed in either the extended edition of this film or else in the final movie, The Hobbit: There and Back Again. As for seeing Legolas again, that wasn't too surprising since it appeared Peter Jackson would bring back as many actors from the The Lord of the Rings as possible. It also wouldn't be that improbable that he was in The Hobbit, since his father is King Thranduil. However, if there is one thing I love that came of this movie, it's the party king Thranduil internet meme.
Something else I think people understandably struggle with is the length of these movies. These film adaptations of Tolkien's work, perhaps more so than anything else, have to be viewed all in succession in order to appreciate the scope of story happening. Waiting each year between theatrical releases makes it difficult to pick up where the action left off, which makes it difficult to become reinvested with what's happening to the characters. It also doesn't help that a lot of the history, mythology, and heck, character development is lost with so many characters and plot meandering all over the place. There is a very good reason these films are dubbed a 16 hour walking tour of New Zealand. So, strangely enough though, my overall feeling of the Hobbit films so far is that there is both too much and too little. By the end of Desolation of Smaug I was incredibly frustrated with the story and how the characters were developing, but at the same time craving the extended edition in hopes it would make sense of the sloppy pacing. I am also really praying to the powers that be that Tauriel won't become another Arwen pining after a non-elf lover, or worse, die off in the coming Battle of the Five Armies. Be a brave warrior woman unhindered by tacky romance subplots, Tauriel. Overturn those Hollywood conventions and rekindle my faith, Peter Jackson, I dare you.
Tl;dr watch some How It Should Have Ended wonderfulness. They'll explain it.