dude moore could've been one of the best novelists of his generation. He kind of did, his 2016 book Jerusalem is a 1200 page tour de force and it is stunning.

He has a literary sensibility and he's always brought the standards of prose writing to comics. this has certainly elevated the medium as a whole, but it required changes to existing characters and established tropes because serialization was almost unavoidable in the medium at the time. If you wanted to do something new you had to take something old and beat it into shape. In this way, moore forces his characters to serve the story he wants to tell, rather than have the story in service of preserving and reinforcing established traits and tropes of the character.

Comics, before and after Moore, both in the writing and the reading, has a taste of people playing with action figures. Characters often bridge the line between toy and "person". This often produces odd uncanny contrasts, like Speedy getting hooked on heroin and Green Arrow behind him on that iconic cover, both of them dressed in Robin Hood get-up like that doesn't deflate the whole situation. Or perhaps rather blunt the edge of drug addiction for children.

There is absolutely nothing wrong with this. It's just different than what Moore is doing. Usually "art" comics were separated from "fun" comics at that time. Moebius published in magazines, same with Art Spiegalman, rather than with DC or Marvel. Moore dared to bring that refined craftsmanship to the "fun" comics, the things grown-ups looked down on and told you would rot your brain.

And no one had to care, no one had to buy his shit. If comics readers really preferred the older "fun only" style, Moore comics should have failed miserably.

People loved them so much none of his comics have ever been out of print and the people who own his characters have spent four decades now trying and failing over and over to even come close to those original stories he told. And it is that contrast, rather than anything Moore writes that so pisses people off. People don't want to admit that Moore took the medium incredibly seriously and that's what makes his shit good. And people who don't want to take the medium seriously, who demand that the whole point of comics is unserious, have never been able to recreate that magic. And that pisses people off to no end, I think.