Is that really a widespread view, Andie? My stance, as a big Tolkien fan as a pre-teen, is that Peter Jackson did an utterly outstanding job in reflecting as much of the scope, flavour and character of the books as could be done in 10 hours or so.
I wasn't disappointed in a single thing in any of them (maybe Tom Bombadil, though he was in truth very cuttable), which is a huge achievement.
But I would say that the films were great because they looked and felt just as they had in my childhood mind. Which is testament as much to Tolkien's ability to evoke and breathe life into such a fantastical setting, as to Jackson's ability to translate that onto the screen.
I think you could argue that the achievement of filming the trilogy was as great as, or in some ways greater than, the writing of the books, given the massive weight of expectation, from backers, audiences, both casual and fanatics, and critics.
But I don't think it really offers more than the books themselves do. And perhaps doesn't aspire to either. I don't think the themes of the books could be heightened further.