You make an interesting point, and I think what's happened is that we're still living with the style and size of the gestures that Wagner invented, but not so much his harmonic language. I think for the most part, mainstream audiences have lost their taste for functional and expressive chromaticism in film music.
Haha I kind of despise choirs of any kind in films these days because, like you say, they're so overplayed. They no longer mean what they used to, and instead just feel like an insincere and manipulative gesture 99% of the time. It's like the film and the composer don't really "earn" them - or else it just feels tonally inappropriate (see: every movie trailer meant to feel "epic" - including harry fucking potter). Or another good example is comparing the original Star Wars trilogy score to the new prequel trilogy. Battles that used to be underscored by Stravinskyish/Holstish/early 20th century post romantic type cues with loads of chromaticism are now replaced with big surging Orff choirs singing long diatonic phrases, and even though Williams is really a very decent and thorough guy, it still feels lame and pretentious to me. I guess you can make an analog to how the gritty and functional production design and VFX of the original trilogy was replaced by clean and pristine CGI.
But I'm also a huge hypocrite and philistine because I love the LotR score pretty much all the way through, although it's not quite interesting enough to listen to on it's own. But Howard Shore is a real dude, and there're reasons why directors like Cronenberg, Scorcese and Fincher have used and continue to use him.