I think it's kind of a status thing really. Black Metal at its core is meant to be elistist, it is anti-metal and is not supposed to confirm to characteristics of more melodic (dare I say "ear-pleasing") styles of metal.
It is an anarchic & outrageous response to all of that, and in some ways, to everything else too.
It's entire concept is inward, self-focusing. Black Metal is meant to be for the few, or the one, not for the many.
Once people realise it was meant to be apart from other styles, that it IS anti-metal, it makes far more sense, even down to the horrendous production values.