[randomguy23]

The thing is, a lot of sexists may be doing it for the reaction from the target - with no reaction, the sexist doesn't get that 'thrill' that they would otherwise get. If the reward is consistently denied, the behaviour may (may) go away.

[natch]

Sounds like you are talking about trolls. I agree those exist but I think it's safe to assume they are a small subset of sexists.