A better question is "why do we care". Software is about the only career I can think of where there are movements created to inject social status into it so that people get into it who are only interested so long as it comes with social status/trendiness. The major also doesn't fix the thought process. You either have it or you don't.
I think it is also the only career which people try to inject diversity just for the sake of it. Maybe I just live in developer bubble and don't know any better, but I've never seen a movement like "Girls do Plumbing!", "Black girls construction bootcamp" or "Mining for equality!".
Yes, that's quite likely. Diversity is important in this field, as in any other, for a number of reasons. The two most important are that is the brings diversity of thought, which should always be welcome in a supposedly fact-based intellectual field, and that it is a signal that we as a society value ourselves and our peers well enough to not treat anybody as second class citizens.