Because, sadly, some women consider abuse preferable to being alone. A woman can read a man's Interest Level within five minutes, but it takes five or six dates for her to read his attitude. If she is sharp, she'll walk. If she is a loser, she'll stay. She would rather spend time with someone who takes another man's ogling as a compliment to his taste instead of a threat to his manhood.
Successful women know life is too short for wasting time on an uptight guy.
A loser, on the other hand, sees jealousy and possessiveness as healthy signs of the man's high Interest Level. Some of these insecure women view an abuser's instability as a sign that he can be controlled and she knows which of his buttons to push. To test her power, she may flirt with another guy in order to start a fistfight between the two men. She gets her way with her manipulation - until she pushes him too far. My point is, some women consistently choose uptight guys.