There is a religious war going on in our country for the soul of America. It is a cultural war, as critical to the kind of nation we will one day be as was the Cold War itself.1
Many metal-heads think that metal died out as a genre because it went corporate and lost its edge. Undoubtedly more commercialized metal appeared, as it always does whenever a genre becomes popular and therefore, profitable. There is more to it than that, however, as larger cultural forces and schemes were at play.
The question of commercialism arose because there was a bridge between power metal/jock metal (e.g. Korn) and more old school thrash metal (Metallica/Slayer) which was never gapped. This paralleled the gap of a decade earlier, when the gap between metal bands like Motorhead and hard rock bands like Van Halen divided the fanbase between album listeners and radio listeners. This gave rise to entire subgenres like black metal, death metal and grindcore which were deliberately designed to avoid having large-scale commercial success. That in turn triggered the rise of the 1990s version of glam, grunge, which was basically slowed-down indie-rock influenced hard rock.