I think these women do it for themselves. Look at Hillary. She wanted some political position so she stuck it out with him...she didnt stick around for love..she stuck around because she wanted something from him. I think a lot of women hang in for reasons other than love.
I recall when I was young, and not married long, knowing this older couple (lol in their 40s). The husband was a builder, they had a beautiful home, cars, horses, vacations, money, money, money. It was also well known that he was a cheat, cheat, cheat. Everybody knew it. I was having a conversation about these people with my aunt, who at the time, was older than them. Why does she stay with him, I asked. She must know..everyone else knows. My aunt looked at me and said, of course she knows..do you see what she has? Do you see the clothes, the money she throws around? How do you think she would live, if she ditched him? So..she looks the other way..and goes about her business.
I dunno. I dont think I could do that..but hey..whatever floats your boat.