Why do Astarion fans love to mischaracterize him?

I always see Astarion with different character's kissing animations, or even dancing like Wyll, I know these things are cute, but at a certain point it's just not the same character anymore. Like, I love Lae'zel, but she would NEVER dance like Wyll, ever. Because that's not her. And that's not Astarion.

I've seen people saying that he's not evil in act 1 but rather neutral (???), I've seen people saying that he would be good with kids (!!!) for some reason.

At this point, do you even like the character or do you like the completely different character you've created in your mind? The so called "headcanon".

I don't see this kind of mischaracterization happening with other Origins, people like them for what they are, but Astarion fans are always creating something new that makes no sense for the character, it's like they only care for his looks and the rest doesn't matter.

Edit: Someone just said "Because they’re just like Cazador and have to make him into whatever they want him to be instead of what and who he is" and I couldn't agree more.