I get asked from time to time why I care about diversity in the communities I'm a part of, particularly the Django, Python, and the broader software development and open source community.
There's a lot of good answers. The simplest one, and the one I imagine just about everyone can get behind: diverse groups perform better at creative tasks. A group composed of people from different backgrounds will do better work than a homogeneous group.
But that's not the main reason I care. I care because anyone who knows how to read some statistics knows that it's ridiculous that I'm where I am today. I have a very comfortable job and life, many great friends, and the opportunity to travel and to spend my time on the things I care about. And that's obscenely anomalous for a high school dropout like me.
All of that opportunity is because when I showed up to some open source communities no one cared that I was a high school dropout, they just cared about the fact that I seemed to be interested, wanted to help, and wanted to learn. I particularly benefited from the stereotype of white dropouts, which is considerably more charitable than (for example) the stereotype of African American dropouts.
Unfortunately, our communities aren't universally welcoming, aren't universally nice, and aren't universally thoughtful and caring. Not everyone has the same first experience I did. In particular people who don't look like me, aren't white males, disproportionately don't have this positive experience. But everyone ought to. (This is to say nothing of the fact that I had more access to computers at a younger age then most people.)
That's why I care. Because I benefited from so much, and many aren't able to.
This is why I support the Ada Initiative. I've had the opportunity to see their work up close twice. Once, as a participant in Ada Camp San Francisco's Allies Track. And a second time in getting their advice in writing the Code of Conduct for the Django community. They're doing fantastic work to support more diversity, and more welcoming communities.
Right now they're raising funds to support their operations for the next year, if you accord to, I hope you'll donate: http://supportada.org