Ask HN: Why were there so few women at Startup School?

I was one of the female attendees at Startup School and I was floored by the gender ratio - being in tech, I'm used to being a minority, but this was possibly the most extreme balance I've seen.

I'm genuinely interested in whether people have theories about why this might be, and whether any women considered attending but decided not to? Or is this simply a real life manifestation of the HN community?