in school at nearly every level, even though they were generally not encouraged to excel as the boys were, since the teachers all 'knew' they would just grow up and get married. The difference between then and now is that as long as the boys didn't absolutely flunk out (and many times even if they did), there would be good-paying jobs for them to step right into. That made school, for most boys, irrelevant. They had it made already. And, inversely, girls could get all the A's they wanted and would find that doing extremely well in school did them little good in the work world because of the societal expectations that they were just going for their "Mrs." degree, or they were only good for being in the helping professions like nursing or school teaching.
That dynamic changed only when it became unlawful to shunt women off into the pink-collar ghetto and women started to be accepted grudgingly in most occupations. Now, EVERYONE has to get a college degree to get even the lowest positions, and there's much more competition out there. Men, in the past, only had to compete against other men. Now there are twice as many people competing. Boys who find school tedious and boring have nowhere to go after they barely pass high school. These are the guys who have NEVER taken education seriously -- and they, along with girls who don't like school, are finding themselves at a serious disadvantage these days. What's interesting is that a college degree today is falling-down easy to get; with the online schools, bible 'colleges,' long-distance learning, community colleges, etc., the standards for passing courses are abysmally low. If you have a pulse and some money, you can get a college degree. (Of course, this has made college degrees useless, but that's a discussion for another thread.)
A third possibility is that boys/men are still in the mode of denigrating certain activities/things as "only for girls" -- IOW, if girls/women like it, do well at it, or have a numerical advantage in it, boys/men will shun it. If that's true, that attitude will bite them in the butt.