  Historically, products of human creativity in any form have manifested itself in various levels of seriousness.
While, some artists have purported their work for entertainment purposes (read: popular music in any form, be it metal), there have been many others who have sought to channelize the human mind to newer realms of consciousness via a visionary theorization of ideals which may be the core or some kind of a personal emotive skeleton upon which their art is based. Whether ideology creates art or vice-versa can be best answered as one cross-creates the other. Sartre and Jeffery archer may both write stories, but it would be criminal negligence on the part of a reader to ignore the finer aspects of a Sartre work and merely absorb its popcorn elements. Such a reader at best can be described as hollow. With regards to Black Metal as an art, the case is no different.
There are various sorts of bands. Whoever feels that the bands they listen to, do not think in a profound manner is simply listening to the wrong bands. A lot of bands have deep ideals and are very well read in the philosophies of Nietzsche, Ezra pound, Schopenhauer etc which is very apparent in their lyrics/interviews. Surely ignoring such aspects of their music is to miss the complete point. But, every consumer has a different level of perception & intelligence.
So, it is ludicrous to expect similar levels of understanding by all. BM espouses a lot of ideals which are very well enumerated in the SRP article already posted here (http://www.anus.com/etc/people/srp/ideas/black_metal.txt ). That is the generic ideology behind it. If certain listeners feel the need the need to kill people and burn churches as a part of accepting the ideology, so be it. BM has been extremely fortunate to have had bands who have led by example. As a nihilist, I wouldn’t condemn such acts, but at this stage in my life, to be caught doing them would defeat the very purpose of them.
At their very least, such ideals are educative and adopting them takes one closer to being a ‘hyperborean’ in Nietzschean terms. So in conclusion, it is unhealthy to assume that ideology is not important. Such stereo-typical, mainstream, hollow thinking has no place in BM or for that matter in any serious music. 
