He wrote the memo poorly but he tried to make it clear that he wasn't talking about individuals.

He was offering a different explanation, based on group averages, of why the industry is unable to reach a 50/50 ratio of male/female engineers. And most of his arguments were based on interests, not abilities.

That's very different from the way it's been mischaracterized as an argument that women are inferior.

Suppose I think my female colleagues can't be trusted to review and respond to my work, because their explanation for demographic imbalances among engineers is that white heterosexual men are racist, sexist, and homophobic. How can I trust someone who suspects me of being every kind of bigot will treat me fairly?