[sgc]

He is not talking about raw programming skills, but the tech environment. And then he goes on to point out how the tech environment could change so that more women would want to be a part of it, or to stay in it longer once they were in.

In other words, he was saying there is something in tech culture which is inherently less palatable for the average woman than the average man. He never claimed that the culture was good and the women were deficient. Instead he said the culture should change instead of artificially trying to fill it with equal ratio hires.