I wouldn't be surpirsed if many of the greatest metal bands (Burzum, Enslaved, Immortal) came from relatively well-to-do upbringings. I have no evidence, it's just an assumption. Here's why: if you have time to contemplate things like music, death, the occult, etc. it's because you don't have to worry about food, money, friends, shelter, etc. It's Maslow's hierarchy of needs, in essence. This is just a GENERAL thought, and again, I have no evidence.