If I was his mom I wouldn't have taken him to that church or faith that brainwashed him into being such an insufferable douchebag.
You're assuming she recognizes the wife needs help and that the wife does.
But these beliefs and this rhetoric doesn't just fall out of men's mouths one day....just cause.
He's a relatively youngish man. He learned this funky attitude somewhere and it has been validated by the influencing women in his life.
Sure, his wife with wither being an appliance in time and likely be abused and/or neglected, but I betcha right now she's all in. She's young too.
This isn't all coming from men. There are women more than happy to throw other women under the bus just for a shot to slaver and lay before a well to do man so they don't have to work, or vote, or take any responsibility for anything.