ICP's fanbase ostracizes themselves so as to be more "down," forms countless free-music-archive tributes to them, and became Christian because ICP told them to do so.
KISS's fanbase elevates a band that played softer rock than Cheap Trick, but did so wearing mirrored glam costumes, to the position of "metal godfathers."
I've seen a 25-year-old with a RECENT Metallica logo/symbol tattooed on his hand.
GWAR's fanbase is basically just there to laugh along, listen to some heavy music, and get their shirts stained. If anything, it's one of the LESS goofy obsessive fanbases I've come across.