1. A lot of people have strong emotional aversion against having sex with random strangers they didn't choose themselves. 2. There's a pretty strong social tab

1. A lot of people have strong emotional aversion against having sex with random strangers they didn't choose themselves. 2. There's a pretty strong social taboo against it and many people will refuse to associate with those who do it. People such as family, friends and potential future employers and mates. You can keep it secret, but that carries its own costs. 3. There's a somewhat increased risk of running into organized crime and/or psychopathic killers.