You've touched on an interesting point here. Nearly everyone I know who dislikes the series don't think that the people who do like it are worng or bad, just baffled at what the raving masses see that they somehow don't. On other hand, for those that did like the movie, those that don't are somehow out of touch or clueless.
It's ironic, since most of those same people would have said the genuine Tolkien fans were the clueless ones just 3 years ago. Jackson has taken the series and, in filming it, has removed it from the realm of the esoteric and planted it firmly in the realm of the popular.
Like 'well it was OK for this to happen because it did this and that'. I am allowed to have a opinion, am I not? I wasn't insulting you, the movie or anyone. I just want to understand the things I disliked and find out how others viewed and liked them.
I want to understand those things, too. It always seems a cop-out to me when someone (as many do) give the answer that "It had to be changed in places, because its a movie and movies are different from books." To me, that's one aspect of the Big Media Lie: "We can't give the context of the President's quote, because it's televsion, not a press conference, and folks just won't pay attention to something on the TV that long." That's spin justifying spin.
Film is one media to tell a story. Books are another. Radio broadcasts are yet another. There are many ways to tell the truth of an event or story. You may have to do without visuals if Gandalf confronts Denethor on audio tape, but you can still imagine the confrontation if the description provided to you is the same as what Tolkien wrote in the story. Where is the need to change who Denethor is simply because the character appears on celluloid and not on paper?
Even most fans of the film that are familiar with the books seem to agree that the movies are at its best when they hew most closely to Tolkien's text, and are least effective when they stray. That the ignorant won't mind because they don't know the story sounds a lot like P.T. Barnum's old adage. (I'll let folks figure that one out on their own.) At its kindest, it could be said that "what they don't know won't hurt them."
In other words, the fans that are most disappointed are those that were promised Tolkien's Lord of the Rings and were given something quite clearly different. And they are disappointed because they know the story and they know what they are missing-- and what's been changed.
In fact, these same fans were willing to compromise: they understood from the start that there would be no Scouring of the Shire and no Tom Bombadil. But no fan I know would have ever agree to Arargorn's trip over a cliff. A movie where Denethor is a tyrant and must be beaten(!) by Gandalf(!!!). Or a movie where The Ents are no longer shepherds of the forest who decide for themselves to go to war, but must somehow be coached or tricked instead. That's what people find so inexplicable. Did it really have to be that way?