To play devils advocate, sexism is a thing everywhere. In some cases, there are good biological reasons why men and women are treated differently, e.g. child care (mostly women) versus hard physical labor (mostly men)
Where those biological differences aren't effective (e.g. typing on a keyboard), then yes, men and women should be treated the same.
But even with that, there may be biological reasons why men and women are interested in different things. Which may mean more women in job A, or more men in job B.
> Maybe other industries suffer less from these things because they have a longer history and have more guild-like working practices, where professional behavior is more clearly defined.
Any job which has "guild-like working practices" is very likely going to be male dominated. Because most guilds were based on men working. e.g. construction, stone masons, electricians, etc. And those jobs are rife with sexism, because of their historical roots.
> I studied CS and I never learned about what it means to be a professional software developer.
Because schools teach concepts, not social skills. They should probably teach social skills and social practices, IMHO. Everyone would be better off for it.