It turns out that rapists like to enter relationships with damaged people, and damaged people have trouble leaving violently abusive relationships. I know understanding isn't a strength of yours, but hopefully this helps.
>nor am I blaming anyone
Saying this doesn't immunize you from valid criticism of victim-blaming. Your question is basically "Why would the victim let it happen again?". I know you're "just asking questions", but we all get the message you are sending here.