Because it's just when someone doesn't get a joke. It's not always down voted; it's just sometimes maybe if it's from a fandom they get angry at you because their fans of something and it's a joke from the book/movie/whatever and if you don't understand then you haven't read/watched the thing and you're not a fan of it or whatever. I don't know, that's my best understanding :P it's not that easy to explain. Hope it helps. And also I don't think it's exclusively a Funsubstance thing but I'm really not sure.
~Guest
~Guest