Why do some men believe that the idea that women don't actually want men is just a myth created to scare boys away from sex?

It's obviously not, there's plenty of evidence showing that women don't want sex. Some women will even tell you this. It's like the whole reason men are being forced into celibacy. Women can easily say no to a man who has never touched her before but when it comes to a man she's been sexually active with they'll just "go with the flow".