But what was "programming"? Was it a skill/profession, or a lifestyle that was being offered to the women? I think it's often seen as a lifestyle - i.e. programmers only eat pizza and wear hackathon t-shirts and spend their free time playing video games. Of course this is wildly inaccurate. Good programmers need to only have knowledge and an interest and ability to learn more - what you eat, wear, and enjoy as a hobby shouldn't matter. But if you go to someone and ask if she wants to give up her own lifestyle and own interests to become a "programmer", she's going to say no.
I suspect that so many people enjoy the stereotypical activities that they're unable to separate out the programming lifestyle from the actual skills necessary.
(Side note: I was however, endlessly amused that the psych course which had 2 guys and ~120 girls had no such concerns about equality...)
Are you saying that the stereotypical programming lifestyle is equally appealing to men and women? Just looking at video games, I don't think that's the case. For instance, I recently started playing Dragon Age Origins, and playing as a female Gray Warden, I kept getting repeated comments from NPCs saying "Really? A female Gray Warden. Wouldn't expect that", and so forth. Why would a woman choose to make a video game that is continuously surprised that she exists? I really enjoyed the game, but it's honestly the stuff like that that tells you in subtle ways that you're not welcome.
Dragon Age Origins is a medieval fantasy setting, right? I guess that they were more concerned with creating a setting that was more in line with our view of an European medieval age-inspired fantasy setting, as opposed to some parallel universe where men and women are equally represented in fighting classes/hero roles.
I haven't played a Dragon Age game so I might be missing something/getting something wrong.
As a side-note, the "a woman to do a man's job, really?" is a common revenge/I'll-show-them trope used to build up to a pay-off involving proving those people wrong. Or just telling them off immediately, but that is a less satisfying variation.
Secondly, I think attributing the mild sexism in the game to intentional world-building is a bit of a stretch, considering that the main religious figure in the game is a warrior woman prophet. I don't think women warriors would be such a surprise in that world! It's more likely that it's just something that came from our current society that got mapped onto the game because the creators didn't think about it. It's unfortunate, because with such an interesting mythology, you could do some really novel cultural things in that world.
Anyways, I've gotten off topic, but I do think there are characteristics that make it easier to blend into the programmer lifestyle (such as video games) and characteristics that make it harder (such as liking fashion) and all of those characteristics contribute to the person's choice of whether to become a programmer, especially since programming is more of an all-consuming occupation than most. And, these characteristics are not equally shared between men and women.
Then in my apprenticeship, we had one single woman in our class. As far as I remember, she only took that apprenticeship because of her father, who was the boss of some IT company. She quit it after three (of four) years. And no, there wasn't even one single comment regarding her being female.
The other girls at that tech school looked at us in funny ways, sometimes saying things like "Oh look, these guys must be the strange programmer nerds! OMG!" - which was funny, because we usually acted more "normal" than they did.
I don't know what it's like today. It's been about six years since then. But at least back then, the women here simply weren't interested in programming. I got to know two female Swiss programmers until now, and I haven't heard from both of them for more than 5 years now.