For dudes, it's projection. For women, they've been mindraped into believing all men are perma-horny nutjobs who see every living female as a source of sex.
There was a story a few years back about some bitch who moved into a neighborhood and called the cops on a 60 year old dude who lived across the street from the park for sitting in the park. She alleged it was creepy he was just in the park "for no reason" and surmised he wanted to fuck kids.
They genuinely think, because the girl isn't ugly or weird in some way, that men want to fuck it. They also believe men don't want or like children. Jewish media is, once again, the explanation.