I thought it was generally accepted that most of the grim overlords in service of the devil arent really being serious... Personally, I find the DSBM bands going on about the joys of suicide are more distateful than some dude shrieking about satan. Black metal does not begin and end with Bertzum, you know?
It's not generally accepted, and they are very serious. The Emperor, Burzum, Dissection murders would be your first clue. They aren't joking.
I'm not talking about dudes like Akercocke, here. I'm talking about the underground BM scene, and yes, many of them are real Neo-Nazis with real ties to real Neo-Nazi terrorist groups in France, the UK, and Scandinavia. Even a cursory look into the sub culture should tell you that.
I just don't really understand why you care. One of the main themes of black metal has always been Satan and evil, and even then 90% of the bands that have a thematic focus on that don't take it seriously.
I still listen to it, but I do prefer not to give my money to right wing extremists, the same way I wouldn't give it David Duke and the KKK.
I could give a rat's ass about Satanism. That's NOT what I'm talking about.