Martin says that we are turning away qualified female candidates right now. That's not the case. Only one female candidate comes through my door for every 7 or 8 males. We are meritocrats like Martin and would be happy to hire females. But first they have to show up.
I don't believe he said anything close to that. Part of the reason posts like this get people fired up is that they assume that they are being accused of shutting women out unfairly. He left open the possibility that women (for example) select themselves out of programming careers for whatever reason.
Imagine if you threw a party and invited half men, and half women, but only the men showed up. Wouldn't you be displeased with those results and conclude that you need to do something different to make your party more appealing to women? I know I would.