Astonishing

I don't know the answer, either:

“I think the greatest, most astonishing fact that I am aware of in social science right now is that women have been able to hear the labor market screaming out ‘You need more education’ and have been able to respond to that, and men have not,” said Michael Greenstone, an M.I.T. economics professor who was not involved in Professor Autor’s work. “And it’s very, very scary for economists because people should be responding to price signals. And men are not. It’s a fact in need of an explanation.”

I've seen a lot of theories proposed.

Some blame employers' growing obsession with credentials. (Diplomas are overrated, officially required, but in fact unneeded for many jobs.)
Some blame the educational establishment. (Hostile environment for males, or something.)
Some blame men. (Lazy immature slackers focused on video games and porn.)
Some blame women. (Willing to sleep with lazy immature slackers, thus removing a major incentive for said slackers to pursue a career.)
Some blame the welfare state. (Women with children less in need of men's money, thus more willing to sleep with lazy immature slackers...)

That's just for starters, of course. As for me, I don't know. I need to meet more of these immature slacker males, so I can intuit their motivations!

I remember advice from a book, some primer on economics, and the advice went something like this: Whenever you see a market behaving in a way that makes no sense at all, there has to be a very good reason for it.

When "senseless" economic behavior is trending,
surely hidden incentives are bending
preference away from what you would expect
the "rational man" to select.