With Amazon's Lord of the Rings trilogy.
While Jackson is primarily responsible for bringing Tolkien's picturesque fantasy to a new generation, some creative liberties he made in the Hobbit trilogy - such as an unnecessary McGuffin and odd representation of a character - are not beloved by avid Tolkien bibliophiles.
The Super Serious Tone
Throughout the three films, the characters and the scenery both resemble the world presented in the Lord of the Rings films. However, the overall tone of the movies is one befitting a deep epic like Lord of the Rings, not a children’s story such as The Hobbit.
Many fans disliked the ultra-serious tone of Jackson’s Hobbit. There are some fun and silly moments in the various musical numbers in The Shire and Rivendell, however, most felt that they are too few and too far between. While the books had ample humor and light moments throughout the story, those same moments feel out of place in the movies.
The Arkenstone As The McGuffin
In the first Hobbit movie, a long prologue introduces the MacGuffin of the movie: The Arkenstone. It is presented similarly to The One Ring in the Lord of the Rings movies, and it has a similar power of corruption. However, in the book, The Arkenstone is not mentioned until Smaug famously converses with Bilbo. Thorin does not mention it until after Smaug is defeated.
While The Arkenstone is presented as a precious heirloom, it was never the entire goal of the adventure from the beginning. It is a clear culprit of run-time padding, and it took away from the beautiful simplicity of the story’s beginning, "In a hole in the ground there lived a hobbit." Further, it detracted from the actual goal of the adventure: getting the dwarves' home back, and replaced it with one where a king wants his crown.
The Spiders Are Everywhere!
In the film, the spiders of Mirkwood were presented as an important group of antagonists that roam around in broad daylight as a symptom of the bigger problem: The Necromancer. In the book, however, these creatures were simply another side quest.
The film used this as a way to explain why The Necromancer would even appear in the film. It is also a thematic echo of the Uruk-hai from the first trilogy; just as the Uruk-hai can travel in the sun, so too the spiders - who normally love the dark of Mirkwood - are similarly empowered by this great evil. Alas, canonically, the spiders have little to do with the returning Necromancer.
The Necromancer (Kind Of)
A large portion of the film is given to the Council of the Wise and their battle with The Necromancer. The Necromancer is eventually revealed to be none other than Sauron, but through the amazing power of Galadriel, he is banished back to Mordor.
In the book, Gandalf eventually explains his constant disappearances were due to fighting The Necromancer, but it is largely left up to the reader's imagination as to what happened. It leaves the reader imagining what could have happened during Gandalf's absences. Peter Jackson indulging in this escapade is understandable in stretching a small literary work into three movies. It also provides an interesting reference to The Lord of the Rings trilogy.
Beorn's Demeanor
Beorn is an interesting character in both the film and the book versions of The Hobbit. In the film, he is presented as a quiet, calm, and collected large man that seems more confused by the introductions of characters and their adventures than intrigued.
However, in the book, his loud, boisterous, and impatient traits help Gandalf introduce each dwarf. Gandalf cleverly increases the numbers of the dwarves as he re-tells the troupe's journey, and Beorn is more annoyed with the interruptions than he is with the dwarves in his house. The exchange illustrates Gandalf's cleverness, as well as Beorn's love of good stories.
Radagast The Brown's Presentation
Radagast the Brown is among the most critiqued character representations in either movie trilogy of Middle Earth. Many people hated his mannerisms, and they certainly did not enjoy watching a powerful wizard travel Middle Earth with bird excrement on his face. In the book, he is only mentioned one time in ing (as Gandalf's cousin), and certainly was not given any importance.
However, since he resided near Mirkwood, it makes sense that he could play a bigger part in a large film production. On the one hand, the portrayal is not all that outlandish; though he was one of the five of the Order of the Wizards, he grew to be so obsessed with the natural world that he remained secluded even during the War of the Ring. Still, the idea that a powerful wizard would go around with bird droppings on his face while riding a sled pulled by rabbits was too much.
Azog The Defiler Is Alive!
Azog the Defiler is a constant antagonist in the films. The hatred between him and Thorin began with Azog killing Thorin’s grandfather, Thrór, and driving Thorin’s father, Thráin, insane. Thorin, in turn, chopped off Azog's hand. Azog is in Middle Earth literature, and he did kill Thorin’s grandfather and father. But Thorin's cousin, Dáin, killed Azog in the Battle of Azanulbizar. Azog’s son, Bolg, led the orcs in the Battle of Five Armies, but even Bolg was not a main antagonist throughout the book.
The orcs' role, regardless of their names, were clearly made to have a constant villain throughout the films. The backstory change made to Azog was unnecessary, even to simplify the drama between the warring factions. Azog was a great villain, but there is greater animosity established in the literature. In the films, Azog lost a hand. In the books, he lost his life. If the orcs were to be the predators of the dwarves, Bolg would have been the best foil to Thorin as both had lost family to the other's family.
Tauriel The Wood Elf
Among the Peter Jackson creations for Middle Earth, there are few as divisive as the female heroine, Tauriel. She is a strong female character that can go toe-to-toe with any of the male characters.
However, Tauriel is not a character in Tolkien canon. As such, every contribution she makes in the movie was either originally performed by another canon character, or was created so she had something to do. Ultimately, though, she is a largely inoffensive, albeit unnecessary, addition to a film in need of characters to pad the run time.
The Elf-Dwarf Love Story
The movies establish that elves and dwarves were not best friends. As Bilbo explains, a broken alliance bred animosity between the two races, and neither one was particularly correct in their dealings with the other. Thus, Jackson decided to incorporate a star-crossed lover storyline in an attempt to quell the hatred.
Since Tauriel was created for the movies, there was no such love story in The Hobbit book. The addition of Tauriel is understandable in order to have a female presence in a story about fifteen males going treasure hunting. However, the nonsensical love story with Kíli detracts from the strong, independent woman she is supposed to represent. In fact, the love story was not even originally meant to be a part of the film; it was added much later in the process through reshoots.
That OTHER Love Story
The Necromancer storyline is expanded in the movies to include the Council of the Wise discussing ways to defeat him. Culminating with Christopher Lee and Cate Blanchett returning as Saruman and Galadriel, respectively, what could have been an interesting side quest for Gandalf is suddenly disrupted by some very strange chemistry between Gandalf and Galadriel.
There absolutely could not have been any romantic chemistry between Gandalf and Galadriel. Galadriel was married, and that was not something elves trifled with. Gandalf was a Maiar, a heavenly creature that took on a physical body. It is one of the most unnecessary and inappropriate depictions made by Peter Jackson. No such idea was ever even hinted at in any of Tolkien's writings due to its absurdity.
