"I would assume that the mere act itself of committing to one woman is perceived by women as a sign of "weakness". It signals that you're putting all your eggs in the same basket, because you can't do better. A relationship with a woman is not a partnership; it's a power struggle. She will try hard to make you commit, but if she actually succeeds, it signals that you're not really good enough for her; she should be able to do better."