One of my basic points about the Peter Jackson Lord of the Rings movies, dating back to my original article on the subject in 2004, is to dispute the defense of the changes to the story on the grounds that (and here I'm paraphrasing the tone of voice used by those who make this argument) "They haaad to do it that way because it's a mooooooovie."
In other words, that there are inviolable Laws of Movie-Making that have to be followed by anyone who wishes their blockbuster not to tank at the box office.
I've doubted this from the beginning, partly because of all the blockbusters that have faithfully followed the then currently fashionable rules (and that's another thing that made me skeptical, the extent to which the rules consist of "whatever worked for the last successful blockbuster") and did terribly anyway, mostly because the film-makers forgot to follow a more fundamental rule, which is "Don't make a movie that sucks."
A couple years before Jackson's Fellowship was released, I got into a conversation with a man who was absolutely certain that the script would have to tear apart Tolkien's entire plot and rebuild it in the form of the Three-Act Structure, because all successful movies had to conform to the Three-Act Structure.
Well, it didn't.
In fact, I am certain that, when Jackson changed Tolkien's story, it was because he wanted to, not because some mythical Laws of Movie-Making forced him to. And this is because Jackson boldly violated the conventions of movie-making when he wanted to. And he endured criticism for it: the prime example is the supposed "five endings" of The Return of the King when it keeps seeming as if the movie is about to wrap up with a celebration scene and then it keeps going. Here, Jackson is trying to follow Tolkien, but he's not doing it very well, because Tolkien's versions of these scenes don't read like a series of postponed endings (and not because you can see the physical end of the book coming up, because in fact 160 pages, in the paperback, of appendix and index intervene between the end of the story and the end of the book).
One major movie rule-breaking Jackson indulged in was to make a trilogy of movies that were three parts of one story (again copying the books, albeit ignorantly). Series of interconnected movies, as opposed to stand-alone sequels, were (unusual? unknown?) then. They're common now, of course, but that's because the rules consist of "whatever worked for the last successful blockbuster" and The Lord of the Rings was certainly a successful blockbuster.
The story of how Miramax wanted Jackson to make two movies but New Line took a gamble on three is well-attested. Here it is retold by someone who was privy to the inside scoop at the time.
Linked to that, here's an article on the radicalism, in movie terms, of the treatment of Boromir's death scene. Key quote:
It would have been easy, following the lead of other early 2000s blockbusters, for the Lord of the Rings trilogy to have catered to the times, and taken a turn for the self-aware, self-embarrassed, and glancingly-to-overtly homophobic. But with the quiet power of Boromir’s death scene, Jackson and company gave the hardened mainstream audience of 2001 a different idea of what masculinity could look like — an older idea.That in turn is linked from this article, more about the book than the movies, concerning the romance between Sam and Frodo. The author threads a delicate line here, because a romance need not have a sexual component, but while I have some issues with this article - for one thing, Frodo is not described as Sam's "mate," it's a comparison - but the fact that the comparison is made is striking - I think the author has valid points.