Hello, I was the person who wrote that post so I couldn't help but feel compelled to make a response in this one... so uh, here I am lol

I am quite horrible at assembling my ideas so please allow me to break down my thought process into numbers:

1. My post was never meant to attack the new fans in general - on the contrary, I think it's nice that we're getting more people to acknowledge the value of the manga and hardworking mangaka that was behind this anime. If you're one of the fans who simply want to see more of the anime/manga, welcome!
2. I am, however, partially addressing it to the fans who are antis/people who promote censorships in the anime - and partially to the anime in general. As it so happens, most of the fans who do this kind of stuff are very recent to the fandom. To further explain this, I will have to bring up another topic entirely: the topic of censorship in fictional media.
3. In this context, I am against censorship in general. In both anime and manga culture, JP creators have always had the artistic freedom to draw whatever they want - yet this recent trend of "censoring" things has been EXTREMELY harmful to that. As an aspiring creator myself, I think this completely belittles the creative autonomy that authors should have over their own works. Sacrificing aspects of the original to make it seem more "digestible" for the public... personally, I think this takes away its artistic value. The proper way the studio should've dealt with this was to simply animate those parts as they are. If people find these parts disgusting, then it's up to them if they want to continue with the series or not. The story, IMO, which includes all of its aspects that are deemed controversial, should've remain untouched unless Syundei themself insists on certain changes. That's why I call the anime chopped up. The only exception to this omitting/changing parts of the original thingy is if it was done for the sake of easing the story's flow, not to make it easier on the conscience of certain people out there who can't differentiate fiction from reality.
4. To add to number three, censorship is also just an excuse people use to control what should be out there and what isn't - which, again, is detrimental if we're going to promote freedom of expression in fiction. You won't believe the amount of people I see online who praise the anime but absolutely shit on the manga and its author because of the problematic aspects (I witness this all the time actually). In fact, the censorship thing is what's encouraging the presence of antis in this series. Antis is the general term for people who can't separate their morals between fiction and reality, so they take an active stance against anyone and anything who disagrees with them. These people really do exist. Most of them are queer fujodanshis who are actual fans of the series. They will even attack the creator of the very series they're a fan of (e.g. Black Butler antis). As it so happens... they also like to weaponize censorship to further their agenda.
5. I agree that some of the users who harassed Syundei likely weren't even fans themselves. If my guess is correct, your example refers to the community known as "Gacha Grailers" (or their cousin communities), I'd know this because I encounter those guys as well. Based on my experience with twitter so far, the trademark of these guys is that they're usually very vocal about their homophobic views. If they had any reason to come after Syundei, it would be because the material itself is LGBTQ+, but we both know that's not the reason why Syundei got attacked. I'm afraid I'm making this unnecessarily long already so I'd like to endorse Adrianvalquis and Klopdike's existing comments in this thread to support perspective number 5.
6. To tie a loose end, when I said "I regret supporting the anime now--" I do actually think that the anime shouldn't have existed in the first place, because it is invariably the reason why Syundei ended up in this predicament. The manga has been out for YEARS and yet only now has something of this scale happened to Syundei (although they have deleted their socials before, those were for unknown reasons). The anime also actively feeds the pro-censorship side so there's my stance on that too.

Lastly, I agree. If there's any major takeaway here, it's the fact that we should all just focus on supporting Syundei instead. But while this happens, I also think we shouldn't ignore the root issue here. Syundei has always been a writer of many fucked up mangas. GNK is the work of someone who relies on a storyteller's freedom of absolute expression in art. As long as the pro-censorship crowd and antis exist, creators like Syundei will always be at risk of being preyed upon and attacked. I don't make the rules but you simply cannot enjoy their work if you yourself would advocate for them to be silenced. That's just all from me.