Because most women are/were a) of average or below average intelligence and
b) generally lazy and hoping their Prince Charming would come along.
For those of us with above average IQs, no nurturing gene and lots of ambition, you could always do something else. It just wasn’t EASY, and therefore, most women chickened out.
However, for most of the 20th century, law schools, med schools etc WERE already open to women.
It is just that most women weren’t smart/ambitious/hard working enough to get into them.
And those professions didn’t interest most women anyway because most women are emotional nurturing followers by nature. Others are hysterical neurotics who have no business in the professions anyhow.
Marie Curie somehow managed to snag two Nobel Prizes without affirmative action. Go figure.
Women only really started going into law and med school when tv shows started portraying these jobs as a) open to women and b) GLAMOUROUS, with b) being the big deciding factor.
Feminism was only ever meant for smart women, who, ironically, never needed it anyway. So it is doubly obsolete (with its own built in obsolesence, no less!)