As a fan of technical death metal and a guitarist it is one of the few genres that has the depth and complexity to keep me interested. This is also why I enjoy music from Sibelius and other classical greats. In contrast, most pop music is so stock that I can guess the next notes in a sequence and it just becomes dull to listen to.

Also, as someone often described as stoic, metal has a enough energy to actually get me excited and feeling. When I listen to it, I get more of a response than say listening to DMB. I wonder if this is related to being an introvert, a lot of metal heads seem like they like to listen to music alone and get energized from solitude, where as a pop music fan may enjoy listening with friends.