I agree with what a lot of other people have said but I think there's also a fundamental undercurrent of readers often taking themselves and their own ideas wayyyyyyyy too seriously. Like it's offensive and targeted and all about THEM if something changes (or grows) in a way they don't like or didn't expect.

Like the example of Gamzee at the beginning of the comic versus the end: the trolls don't fully get introduced until the beginning of Act 5. Murderstuck happens around the end of Act 5. So you have about 2000 pages of "early Gamzee," and then twice the amount of pages of that are Act 6, where Gamzee actually does things. Interesting things! He just struggles to be a Tumblr SexyMan Villain because now he's distasteful and unpleasant (which wasn't far from his early way of acting, just now openly and actively malicious instead of harmless). Which is honestly a genius flip on that trope.

And I feel comfortable saying this because I also read The Serendipity Gospels and was a GamKar fujo when "Palemates for Life!" was written (sheds tear for middle school me). But just because I liked it doesn't mean that it was accurate to the story and the actual character that was written - and actively being written! I think if the alternative to fans sometimes being a little butthurt because they guessed wrong or forgot the story was still ongoing is a story where nothing ever changes... then yeah fuck them fans. Save it for the fic.

Homestuck is a meta heavy story, which means it has to grapple with the way it itself gets read, that's just a part of the genre. You could argue that something like Umineko is VICIOUS towards readers, actively painting large groups of fans as active, stupid, and malicious sheep. But because if anything Umineko asks for a lot more from readers than Homestuck does, they're ready to bridge that gap and figure out if it really is talking about them personally, instead of latching onto a "fan insert" as a representation of Everyone In The Fandom. Calli doing something silly isn't calling every fan an asshole lol.

I truly believe that any work that puts stroking the ego of it's audience first is doomed to failure Because it can never challenge them. It can't risk offense, it can't risk pushing them to reconsider, it can't grow and have the reader grow with them. It has to center the reader as someone who is always right... it's patronizing, and really just treats the reader as an idiot! I think it's actually a big issue with a lot of books these days... if you don't follow e-flux/haven't read Anna Kornbluh's Immediacy: Or, the Style of Too-Late Capitalism it really dives into how catering to the audience has actually hurt us more than anything. It's a dense book but Isadora Neves Marques wrote a great article that touches on some of it's big points: https://www.e-flux.com/journal/155/677214/how-to-be-responsible-irresponsibly-on-art-beyond-immediacy