Weird Erotica?

You guys are kinda heading in the right direction. But my original question is not, "What's with this shit?", I understand different people have different fantasies and whatever. What I really want to know is why are 7 or 8 out of every 10 erotic stories on writing.com these kind of stories. Especially among the choose your own adventure genre. It's just like there's no variety, and I'm just curious as to why. Is there some (coincidental or otherwise) connection between people who use writing.com and people who get off on this stuff?