I'm not necessarily talking about HN, but about people I have known in person - classmates in college, people I knew socially afterwards, and (this probably has skewed my judgement somewhat) an ex-boyfriend. I also personally suspect that the phenomena may even be making some hard-to-trace contribution (through reduced opportunities to practice communication skills, limited peer groups, and less time spent studying human diversity and other cultures in general) to the headlines which keep popping up about how sexist the technology field is. I know that concern may sound extreme, and I really hope that it can be proven wrong. Obviously (and thankfully) none of that can be generalized, but the original poster's example was so shocking to me that I felt compelled to say something warning people that the situation is in some cases possible.

I also don't know what you mean when you say that people with technical knowledge (which I have some of) are "more rational about their opinions and conclusions" - I sincerely believe that taking a literary theory class and learning about often-vilified (perhaps not here) ideas such as postmodernism and deconstruction improved my decision-making ability by allowing me to better understand both sides of an issue.