I'll try to steel-man the OP's argument. The notion that there's both a biological component and a sexism component to the statistical divergence between equal-sex representation in CS, should not be contradictory. OTOH, if someone is primed with an argument about the biological component, they might behave differently when encountering a female peer. So, for instance, there's a psychological component to reading Damore's memo, and even the most objective of minds are vulnerable to a subconscious bias. Furthermore, a genuinely sexist person could easily shield themselves with this argument to justify conscious and biased sexual discrimination.