I think that has more so to do with where you live and/or the types of guys you go for. I live in metro DC and based on what I see and hear in this region, black guys generally have a preference for other black guys. You can generally pick out the black guy who has a "preference" for non-black guys quite easily.
There are interracial couples, yes, but you don't see widespread interracial mixing in social venues. More often than not, you have one or two black guys in a venue of majority white guys (of course, it's never the other way around).
I can't speak to what type of guys you "prefer," nor to the availability of that demographic/people who fit that bill in your area. I think one of the big problems is that people may often try to go for someone who doesn't necessarily like their type.
