Nancy Folbre explores "girly jobs" and the reasons why women are still willing to accept less pay for more value. One study shows "men do not value women’s intelligence or ambition when it exceeds their own." I'd add that women still accept men's valuations when they shouldn't.
One irksome reality:
A really good kindergarten teacher is worth $320,000 annually, according to one recent estimate, well publicized in this newspaper. That would reflect the present value of the additional money that students in a really good kindergarten class can expect to earn over their careers. But average pay for kindergarten teachers is only about $50,380. And even at that level, kindergarten teachers, many employed by public-school systems, fare relatively well compared with those in similar jobs. Preschool teachers, who are typically responsible for only slightly younger children and don’t belong to teachers’ unions, earn, on average, about $27,450. (Animal trainers, by comparison, take home on average of $31,080.)
And then there's the safety factor. Women don't always feel "safe" in what is (wrongly) a man's world.
In our society, caring for others has long been considered an essential aspect of femininity (social psychologists devote considerable effort to measuring such things). And sometimes women don’t choose girly jobs, but end up in them because they face discrimination or harassment in other jobs.
Women value jobs with social value, too. The market place doesn't have that much respect for social value in America. Do we change that or do we just accept that as the norm?