I thought dextorious's comment was intended to satirise both the people who complain about sexism in hacker culture, and the people who insist there's no sexism in hacker culture.
I have to admit, I did sense a hint of sarcasm to the post but I suppose it was too subtle for me.
It's unfortunate that dextorious's comment led you to believe that people opposed to sexism were making assumptions.
I was just mocking similar responses prevalent in a lot of HN comments...
http://www.amazon.com/Unlocking-Clubhouse-Computing-Jane-Mar... is a pretty good academic references, with plenty of examples of parents who actually do do this (teach sons and not daughters), hard research, and practical solutions. luckily it actually isn't that hard to start on the path to fix for those who bother to find it an issue (CMU and MIT among them).