Prostitutes upset the sexual market by providing easy access to NSA sex with (in some cases) attractive young women for anyone who has the money to pay for it.

Some men and women want to keep certain men sexually deprived. Some men can maintain a sense of superiority by ensuring that other men don't get laid.

Women can use the denial of access to sex to try to coerce men into spending on their money on long-term relationships with used up leftover women instead of spending it on casual sex with young nice looking hookers.