Very often people's sexual fantasies revolve around some forbidden thing. Basically what THEY consider forbidden. If you look at the data that pornhub published, people tend to search out videos based on region. Like people in NYC will search "Dominican" because they are a prominent minority there. I have a Dominican friend there who gets frustrated by people seeking him out and acting weird like it's some taboo to date him & he ends up just getting grossed out by the whole attitude.