While I'm not against minor key music, metal is mostly written in the same modes (I'm not sure it even makes sense to say "scale" here). This means you have roughly the same intervals being used again in layers, which reduces the music to mostly rhythm, which also means it's immensely repetitive. Contrast to classical where setting the base key/scale is a method to achieve variation from that standard, but only in the context of it; it's much more orderly than idiot jazz or even, sadly, the somewhat primitive methods of metal...
Let's get away from the kiddie music.