It took me years of therapy to see that my mom (who stayed in an abusive situation) was actually very very strong. She made sure we had what we needed and that my dad would provide it. She is a very smart woman too and worked on his strengths (he was a hard worker) to get what she had to for her kids.
It was a different time though, she was a stay at home mom. I know my dad loved us but he had huge huge issues he never dealt with and he brought them to his family/wife.
And honestly, I think the reason my mom stayed was that she was truly in love with him. It makes no sense to me knowing what I know now but I can't say she made a mistake, she did what she could with what she knew.