The problem which career women face, is that THEY demand a man who is of higher status than themselves (though they might grudgingly settle for equal status). Men, on the other hand, are looking for a WIFE, someone who will be willing to keep him sexually satisfied and bear and help raise his children, and are willing to look at women of lower career status.
In other words, the only men the aging career women would be satisfied with, have better options than to marry THEM.
By the time many of these women decide to start families, the men they want to marry can afford better wives.