So the OkCupid guy did a great book chapter on how the best way to get a lot of responses (as a girl) on OkCupid was to be a bit off the bell curve. In particular, he found that girls who were tattooed, or had piercings, or were otherwise off the bell curve (there are many ways to do this) were rated low by some, and very high by others and did much better than people who just averaged the same rating.
Does this explain fetishes? Humans are weird. In particular, we now have the "big data" to answer the questions we are maybe not ready to learn the answers to. Everyone in the news is amazed that we can pretty closely estimate the number of gay males in America using Google search data. But that's just peanuts compared to the sexuality differences you see among FetLife users, or Fictionmania browsers, or Literotica readers.
I will use this one person as an example from FetLife:
This is a shared fetish list with at least one other person. (That's how FL works). Perhaps if you are off the bell curve enough then you are a 10 to someone? I think society has yet to deal with just how wide the bell curve is though...