there are many kinds of metal, death metal is the one that you are talking about for example. its just one of the things societies do i suppose. along with assume things are true when told something without looking up the facts themselves.
I'm a big fan of "lighter" metal, such as Nightwish, Evanescence, Within Temptation, Apocalyptica, Sonata Arctica etc. You probably can glean what I like from those examples. I have enjoyed heavier metal as well, like Children of Bodom and Kittie, but I'm... less of a fan of those than the melodic, lighter kind.
