Yes, exactly: Maybe men irrationally pursued more PhDs than made sense, while women made more logical decisions all along, and men's lower rates reflect them improving their life choices.
Maybe both men and women irrationally pursued more PhDs than made sense, but the men were historically more likely granted the opportunity to find out for themselves why it was a bad idea ;-)
(I get your point though. "Just sayin'", as the phrase goes)
Aren't the "worthless" (market-wise) degrees (humanities, social "sciences", etc.) mostly women? Also, many men pursued CS even back when it's wasn't such a lucrative career. I'm not convinced that people choose their professions particularly rationally...