I remember people complaining about Elves at Helms Deep completely ruining the movie adaption, now it's Elves having the wrong hair cut ruining their childhood
Is it really that hard for a billion dollar production to give a third (I'm assuming) of the character cast some nice flat human hair wigs though? When you see a scene set in Rivendell in the LotR movies and everyone has long shiny hair, that's part of the look.
I really don't mind racially diverse casting, most of the film industry in the past few years has been reduced to remakes and adaptations of properties full of white people, and actors who aren't white have to work in these conditions. That's not what I'm complaining about when I talk about the look, though it would be nice if they would make it make sense, and take, say, a few important families or a whole branch of Elves like the Sindar and make them all different.
PJ took some huge creative liberties with the plot and some of the characters, and yeah, something like Elves in Helms Deep is a problem there because they take you out of the immersion and go against one of the core elements of the book, which is that Elves are in soft retirement from the world and not there to solve problems or take so much part in the action that they should leave their home that needs defending and go and help humans. In fact, it goes against another changed part in the movie, where Elrond is convincing Arwen to go with the rest of their kin right now - so Elves that still have business in Middle Earth are actively leaving and not waiting at all but at the same time they are so involved that they send troops to fight with humans? And they don't really add anything or solve any excitement/pacing problems in Tolkien's plot - Helm's Deep is already an exciting filmable part of the story full of moving parts and they are already expecting an influx of warriors to come in, so it's just a plot point that repeats itself.
But PJ is forgiven for these small sins by most of the fandom because every place and character had the look and feel of the books, while still being perfectly acceptable to audiences at the time; and while one or two core elements of the books have been messed with in a few isolated plot points, not all of them have, and the most important ones have been preserved. In fact, it's possible that when this is over we will start looking at LotR movies like the one successful adaptation of a popular fantasy book. Nothing else ever came close and I don't think this will either.