Pardon the anonymous ask, but it feels very strange to watch the discourse happening. (No shade to you, I quite like your response and find it very mature actually! I mean more in general.) I'm in my early twenties, and I remember being a teenager and being caught up in fandom discourse like that which, fundamentally, did not matter in the long run.
I think that really, truly, people need to remember that the block button exists. It's up to everyone to curate their own experience, and we really have to remember that our dislike of something is not worth moralizing over. We can just dislike something and move on! We all have different tastes and sensibilities, that's just being human. That, and vagueposting about someone on a public forum, in public tags, is just never going to benefit anyone! It's petty and opens up harassment.
Certainly, people can feel their feelings, but at the end of the day, it's up to everyone to have some decorum and not do something like that. It's not a flaw to just whine to a friend in a private chat instead of projecting into a public forum, and then move on with our days. (Hell, I've done that! It's healthy to feel our feelings, we just have to manage them in a way that is responsible and doesn't hurt other people). That's my piece there. Again, I really like your post response a lot.
I don't like the idea of calling responses 'mature' or 'immature', because at the end of the day, people are just people. I just curated my thoughts more for this time round, as opposed to putting stuff out exactly what I think, because the fandom I'm addressing has more adults in it than children. I'm going to curate my response more in that manner for fandoms I'm in. I don't see the point in actually engaging with people when people refuse to engage, after all. And most of the time, I find children less likely to be interested in engaging in points when they've been told to think one way.
As for the rest of this ask, I do agree whole-heartedly on the whole 'block and move on' as well as projecting into the void versus chatting to someone else. I'm not going to act harsh against the user that decided to be an ass once - as long as they realize their mistake and don't make a fuss again, things should be peachy. I'm glad there are people who also want to call things out, but it was obvious from the way that person wrote they were jealous of a particular person I happened to become friends with. And it was clear at how offended they were about not being taken as seriously as they hoped. I can tell, because I have a similar issue brewing inside me whenever I see more skilled artists. It's something I kept to the backlow, and hanging around with other artists has made me forced to realize that it is there. The only way to make yourself better sometimes is to express more through art, not through putting others down.
Also, if you (gen) can't handle things like obsessive/possessive behaviour, and codependency issues... do you really belong in fandom in general? Most fandoms explore the concept of yanderes and stalkers, some with a lot less tact than others because they aren't thinking of things. It reminds me of how Sans was reduced to a guy who didn't care about his brother's death, when really in all the routes that aren't pure Genocide, he absolutely is pissed off at not being able to do anything to you because you aren't dangerous enough for him to get involved. Heck, even now, Sans Undertale is still mischaracterized along with Asgore Undertale. The attempt by the fandom to 'reverse' this portrayal to make him a crybaby just shows how little they understand the character in general.
I'm just saying, that the person making the Yanward AU has a lot more tact and understanding of what's going on with the characters than the person calling out that particular trope. And I don't like it when people want to burn the forest because they don't like one specific tree in the entire vicinity.