I dont think it's actually that surprising tbh. I think it was inevitable that someone raised in a family with such warped ideas of sex, relationships etc well one of them.would have cracked /got things massively wrong.
The parents were always pawing at eachother. Sex was a spousal duty and the girls were taught to always be joyously available. Not something between 2 consenting adults.
If divorce is more immoral than this there's no hope. I know people fund it horrific his wife stood by him.but what else could u do with 7 kids and no means of supporting yourself. The whole stance om contraception leaves these women trapped.