Twitter has confirmed for me something I've always suspected: humans need to hate and ridicule just as much as they need to love. And even if you created paradise on earth, people would eventually feel compelled to graffiti over its walls.
We can use non-psychoanalytic terms if you wish. The irrational brain. The reptilian brain. The bestial aspect, ruled by dream and emotion, that is often self-destructive if left unchecked.