The actual cost of getting into craft brewing can be prohibitive on the production side. You're generally talking about middle and upper middle class people who do it. Culturally, the craft beer fad started with hipsters, who are generally white. Just as you now have a growing black nerd and black gamer culture, I expect a larger portion of the black community will start to get into craft beer in the future (similar to the way white kids adopted hip hop, but in reverse).