A similar question was asked in the Spinal Tap movie...
I had a friend who is mixed-race and she went to see Enslaved live and after the show she spoke with Grutle and her race came up as a topic of conversation. Apparently, he was a little bit surprised that a non-white person was a fan of Enslaved, and BM in general. She said he was very pleasant towards her, but was just generally curious that a black female was a fan of BM.
What do other people think is the reason that Heavy Metal, and BM, is generally only listened to by white people? Of course, there are Oriental bands and fans, but generally speaking the fan base (from my own experience and observations) is largely made up of white males. With the exception of the obvious reasons such as NSBM, does anyone else have a theory why the scene is the way it is in terms of racial make up?
In all seriousness though, I would attribute the predominantly white racial make up of heavy metal/ black metal/ etc, to the countries of origin where most of these bands originate from, combined with the alternative appeal of those styles of music. I really don't think it's anything more or, heaven forbid, "in the blood". Some black metal also has a strong pagan influence which I'm sure resonates with impressionable white males interested in their heritage (sometimes with questionable results, e.g. NSBM).
In the end, music is music and the good stuff will always resonate, regardless of ethnicity. Whether some forms of music should only be listened to by certain types of people is utter shite, and just high school mentality elitism.