10:44 AM on 01/29/14
They pretty much only cover: pop, rap pop, country pop, rock pop.
Black Sabbath won best metal act in 2014, and they didn't even air that. The Grammy's only gives airtime to what's really popular, and straight up hip-hop is becoming less and less popular.
Edit: I'm not saying there's anything wrong with how the Grammy's operate, but to demand more specific subculture and better art from them is futile.