If a girl is attractive, she is going to have loads of "nice guys" coming up to her everyday asking her out in unconfident ways. By being a cunt and just ignoring them it's better for everyone in the long run as they don't waste their time on someone they have no interest in and the guy is given a clear message to leave it alone, sparing him any further harm if he thinks he may have a chance so keeps chasing just to find she was just being polite with his advances.