The producers want to sell the film to those who have not read the novels, thereby appealing to millions more people, thus selling more tickets. And for that reason the movie must be appreciable to all those who have NOT read the book. Dune was a perfect example of what not to do. If you knew and liked the book, you probably liked the movie (or at least appreciated it). If you had not read the book, your response to the film was likely, "Huh?"

Now the ideal scenario is to make a movie that satisfies both parties. The producers want to make the Tolkien fans happy because that means multiple ticket sales to one person, video sales, pay-per-view royalties, merchandise sales, etc. But from a financial standpoint they cannot produce the film at the expense of the non-readers. That is where the director comes in and one hopes that he/she, the actors, screenwriters, and producers can collaborate to create a film that is a great seller to everyone. But a word of warning from me (someone in the know), "Do not expect a direct and exact reproduction of the book onto film." For one, it would be a failure. Try reading the dialogue, picturing the scenes, capturing every event and every character in 3 movies (even if they were 3hrs each which is the ultimate limit). Wouldn't work.

So, my little piece of advice which you may take or leave. Go to the films, enjoy them as a movie representation of the Lord of the Rings, as envisioned by someone else. Revel in the fact that you are getting to partake of this great work in another format. Think of it as listening to music that represents a piece of art, or a painting of your favorite piece of music. Film is a different medium, enjoy it, take it in and revel in what you have been given. Critique it if you wish, compliment it, but do not expect film to be a novel.

That is all I have to say about that.