Hey, man! There are two uses for the noun, “man.” One is as a word for any human being, “featherless biped,” person, homo sapiens, et cetera. The other is as a noun for a male man (not a postman), a male person, a homo virilis, a bloke. The first is general to all human beings, while the second is specific to a male person. Thus, to call a fireman, postman, policeman, and such doesn’t show hatred to women in any way, but rather is inclusive of them.