Well I was in an engineering class where the professor said to the female students, "you shouldn't be taking this class because you are taking up valuable space from better engineers." Shortly after he was forced to retire. This was early 00s. Even if those departments aren't hostile to women now they were hardly welcoming to them in the past. Engineering and CS have the perception of being hostile to women in a way that other science departments (biology, math, even physics) do not.