Lol, okay, I didn't read any comments, so this might have been said already.

I don't like yandere characters because they're romantic. I like them because they're flawed. In some ways, they're more true to actual human beings than all the shounen main characters and shoujo jesuses in the world. Lots of people have something that can make them snap, or break, and they're just examples of that.

Obsession is something that has been dealt with in fiction for ages. People can like obsessed and yandere characters without thinking their situations or batshit insanity is romantic. It's just another type of character to explore.

Also, where are you? Everyone and their mom is obsessed with Rollo.