If no one gives a shit about who writes functions, then why are women so underrepresented in computing? Do not say it because women don't like programming or engineering, because that's clearly false. Women had much more representation in the industry 30 years ago. It's been declining over the years while the frat boy attitude in the workplace has been going up.
If you're perfect, then great. But there are many men who are offended that women would even compete with them, many men who intimidate others especially women, many men who think telling a dirty joke is proper on-the-job conduct, many men who see discrimination but do nothing about it and thus reinforce the status quo.
I'm old enough to remember when people claimed there was no racism in the 70s either.
To answer your first question: Women aren't underrepresented in computing as much as they're underrepresented in many computing-related roles. There are, for example, very few women code monkeys who are willing to replace their social life with writing software. This has nothing to do with how good they are at it, but more a) that they value a social life more than individual accomplishment, b) don't want to spend their time fueled by energy drinks in front of a computer in dim lighting surrounded by overweight sweaty men with pizza stains on their shirts, c) don't want to have to deal with the large number of social misfits such occupations usually attract, and d) the hiring managers tend to hire the people most like the ones who currently are their best performers (which makes getting women into the roles in the first place very difficult).
Plus, there's the whole education issue; women often don't get the training in the first place to even place for these jobs, due to societal pressures, having to deal with those same people in school, and choice.
So... we talk about women being underrepresented in computing mostly because these are highly paid jobs. We don't talk about women in garbage disposal being underrepresented, even though the ratios are similar and likely the reasons for underrepresentation are also similar.
The truth is that there HAS been centuries of mysogeny at work, and some level of gender bias in the other direction is needed in order to combat the pressures that have nothing to do with individual ability. As such, this sort of test is useful at measuring current norms.
HOWEVER, this sort of test is NOT good at gaming gender bias or effecting change. That has to be done on a much more general level. Getting your three female coders to specifically write code that depends on each other's code doesn't really change anything other than the test results. Encouraging the daughters of all your coders to come in and see some of the rewarding things their parents are working on could have a much more significant long-term effect.
That said, I recently had to have "the other talk" with my kids -- the one about racism. Not because people were being racist, but because they stumbled into "affirmitive action" plans that made absolutely no sense to them, and they couldn't figure out why people would set up rules like that. It was equally incomprehensible to them that people would link intelligence/suitability for a task to someone's skin colour or grandparent's continent of origin. But if my generation hadn't had those affirmative action campaigns, my children would now know exactly why such plans are (still) in place.