I never said any of them were perfect, I said they were good. There were things that I don't think were necessary - Arwen, for instance, having an action scene didn't contribute a lot and made the rest of her appearances kind of jarring compared to the woman we'd been introduced to. Gimli and Legolas lost a fair bit of character to become iconic stereotypes with too much comedy, though at least they got the growing friendship part right. The Army of the Dead was silly. Saruman's fate was either really corny or just completely not addressed depending on which edition you watch. Aragorn falling off a cliff was a pointless addition that I'm pretty sure was only there to give Liv Tyler a role and keep the audience from forgetting about Arwen in between film releases. There's probably quite a few more, if I cared to dig them up.
Out of ten-ish hours of movie, these don't add up to a dealbreaker. If the result resembled the Fellowship of the Ring SNES game,
that would have been an affront to all things good. And I don't think they say, "I think it should have been written this way" so much as they do, "I think it
could have been written this way, and it would still be good, and I think this would make a better
film." Changing things to appeal to your audience is a fairly major part of adapting a work, so I'm not sure I see the problem here.
Could it have been done better? Yes, it could've. But I still think it was done fairly well.
Of course, I listed all my little gripes about the Hobbit
here, if that's what you were talking about, but much the same conclusion applies. The major difference is that I would consider the Hobbit adaptation to be vastly superior, and that they actually achieve some degree of cultural evolution. LotR was just the source material run through the Jackson Filter with little of value added, resulting in a product that's still excellent largely because of its original qualities and the excellent visuals that come out of that filter.