Language is both evidence for and part of the patriarchal oppression of women.
Grammatical gender has nothing to do with social reality. There is therefore nothing offensive about saying "everyone has his own life to lead". Furthermore the systematic use of "his and her" is clumsy and "their" is incorrect, since everyone is singular. Most attacks on gender bias in language fail to recognize contrasting patterns of language in other cultures, even within Western societies. Thus German distinguishes "Mensch" (not animal) from "Mann". A German women is therefore far less likely to feel excluded by the use of "Mensch".