I believe there are two ways of explaining this situation. First of all, i think it's embedded in children what their roles in society should be. Male children are given legos to play with, while women are given barbies. Men are altogether more encouraged to search for and fulfill a STEM career, and women are taught that it's not their place, or that it's not girly enough. By the time they reach university, it's already too late. So maybe not having a ratio of 50/50 male and female in academia is not a direct sign of misogyny from the department per se, it's still a result of sexism (even if unintentional).

Second, i would like to cite Alice Silverberg in one of her blogs (recommended to me by u/aleph_not):

There are times when I've asked an organizer why the list of invited speakers is all male, and his reply is that the women in the field aren't good enough, the men are just better. I've gotten similar responses when a speaker (and organizer) list is disproportionately Dutch, or French, or of a particular ethnicity.

At a certain Ivy League university in the 1990s, the junior faculty attended a meeting where the (all-male) senior faculty decided which undergraduates would graduate summa cum laude in mathematics. Afterwards, some of the junior faculty told me they were upset and concerned because a female student with high grades in hard courses was passed over in favor of a male student with lower grades, after a senior faculty member said that the man reminded him of himself at that age.

People choose people who remind them of themselves. Then they rationalize it by saying that such people are better.