>>82058796 (OP)
Because of the evolution and natural selection.
During most of the history it was patriarchy and rape culture. Women didn't really have a choice regarding mating partners. Society custome, laws, morals all were on the side of man forcing himself on a woman. do you that prior 1970s marital rape was legal in every country?
So women didn't have choice besides laying there and taking it. This is where natural selection kicks in, women who hated that much surely were at disadvantage in probability and amount of of kids they could birth. Women who were ok with rape had much higher probability to have kids and and larger numbers. So women with rape fetish gene simply outbreed women without such gene.
Not all marriages were abusive in history of course, but this gene is nice to have for woman without downsides (in patriarchy). If woman doesn't have abusive partner, it's fine gene doesn't hurt. But if she runs into rapist, this where rape fetish gene kicks in and greatly incresied chances of reproduction of this woman.
But without patriarchy this rape fetish genes is great hurt for women. They unconsciously seek rapists and abusers and meeting such man is nothing good for their life.