Sure, the grey zones might be hard to pick out but it does seem like there are some clear extremes. "Locomotive engineers and operators" is 92% male yet "Registered nurses" is 87% female. If you look at all the male-dominant and female-dominant occupations, there does seem to be some sort of pattern which (for lack of more precise terminology) seems to be well-described as "people-oriented" and "thing-oriented".
Go through the list, look at the entries which are either <20% female or >80% female, and tell me if you don't see the same pattern:
Go through the list, look at the entries which are either <20% female or >80% female, and tell me if you don't see the same pattern:
https://www.bls.gov/cps/cpsaat11.htm