True. You did a good job trying to show his own contradictions and blindspots. But some people don't want to understand.

The way you tell the story, the impresion I get is that they miss the "submisive wives" that needed to be like that because they had no options. And part of being the "perfect wife" was pretending that you were happy, hide when you were unhappy to "not put an extra burden in your husband". Of course their mothers won't tell them "Actually, I was unhappy with your father" and their fathers would tell them how great everything was.

But I don't think some of them do know that women weren't happier, but since they want that, they would lie and try to persuade women of that. Others decide that "if the husband is happy, then the marriage is happy", doesn't really care about how the wife feels. It is just assumed that the wife's happiness is either secondary or dependant on the husband's. I've seen this mindset several times. They just can't understand why you don't do what they want you to do. And they are unable to see that many women are happier now.

My guess is that they don't want to admit that marriages weren't that good for women back then, because that would mean that they are the ones who need to change. And they don't want to change because it worked for them.

Anyway, marriages lasting less doesn't mean being worse. In fact it could be just the opposite, marriage being better while they last. People only working to remain married to people who make them happy and people being single if they can't be in a happy marriage.

At the end of the day, people would do what made them happy.