"Why are women like this?"
It's for one of two reasons:
1. Because she feels insulted that he made a move (because he's ugly) and she has to make sure he doesn't make that mistake again. Teach the ugly man a lesson for the future. Remember, females are a hivemind.
2. If he's not completely ugly and normie tier, it's a way of passively bragging to people that he made a move on her.
Tl;dr
Looks are everything.