It's the same systemic bias lots of nerdy computer projects have. Please excuse the following potentially racist speculation: black people have more trouble acquiring the money, encouragement, and time to be a computer hobbyist. Bitcoin is still a luxury.

It's a problem. In fact, a group of people frequently abused by cops, voters, and regressive inflation taxes might have a lot to gain from Bitcoin. So what can we do to counter this bias?
A. Nothing. If/when Bitcoin goes mainstream, everyone will use it anyways.
B. Focus on projects which will benefit black people.
C. Inform blacks in your community about Bitcoin.
D. Donate Bitcoins or Bitcoin-related USD profits to black charities. That will get their attention! :-)

Probably more I didn't think of. The main benefit is of course that the internet is post-racial, and the efforts of racists here will inevitably fail. In not kept down, blacks will rise up.