"Most people get more love than they deserve." - Bertold Brecht
When you marry, sex stops. When you commit, expectations rise. However, if you are seen as very incapable in the romantic department, women will struggle to make up the difference. This is why they will ignore perfectly good men and devote decades to men who only use them for sex and comfort. Women don't want a man who loves them. Women want a man they have to continually work for.
They cook for him. They take his car to the shop. They don't care if he cheats. They don't care if he is a slob or has horrible personal habits. If he is hard to get and hard to reform, he must be the greatest thing on earth.
Sadly, most women spend most of their lives on guys who aren't worth shit. That gives most other guys license to treat women any way they please. Why be devoted, or loving, or kind, or exclusive or decent - when those are the last traits women seek in a man?