The etymology of the word "man" is completely irrelevant to its present use. This isn't some obscure term like "ironic" for which it would be reasonable to claim that common usage is mistaken - this is one of the ten most common nouns in the English language. The common usage is as the only formal term for male human beings.

Were this thread a discussion of the evolution of gendered terms in English, your remarks would be apt. Were it a novel argument in the dialectic of gender in English, your remarks would be apt. It is neither.