This is disingenuous. "This is not easy to explain to women..." is saying that women categorically would struggle to understand it, to the extent that they need

This is disingenuous. "This is not easy to explain to women..." is saying that women categorically would struggle to understand it, to the extent that they need to be mentioned as a separate category in addition to the "mechanically innocent." It's not simply observing that fewer women would be interested. The other flaw in your argument is that casual sexism like this is why women are less interested in mechanics (or at least appear that way). If I lived in the 50s, why would I want to read a publication that casually implies I'm not smart enough to understand it? Candidly, the number of commenters willing to defend casual sexism is a big reason why I've lost interest in Hacker News.