Yes, that is it's literal meaning, but the point is that it is uncommon to use female as a noun in reference to humans except when speaking clinically or when chauvinists use it as dehumanizing language. The word "women" is the much preferred option by most women, so the use of "females" in this context suggests that OP may have been speaking derogatorily.

I don't see how this response is relevant. Their point was that the word "female" in the OP is used in an irregular, potentially chauvinistic, way. The etymology of the word is irrelevant to how it was used in this case.