I find your description of death-metal entertaining because of history. A reporter sent to the first Jimmy Hendrix show out of the state of Washington on his first tour was asked what Hendrix's music sounded like. He said it was like heavy pieces of metal being dropped and banging together. This is where we get the phrase Heavy Metal.
Without naming specific bands, I can't say what appeal the music has, but for the most part...
Pop is usually dance music. Hip-Hop, Rap, even 80's Pop and 70's Disco (which sounds almost exactly like today's hip-hop to me). The people who like POP usually like to dance, and this music is perfect for their style of dancing - and it's not the two-step.
I would describe death-metal as melodic noise. As a musician, I can find the chords and rhythms, and actual musical content, if I look for them. Death-metal is raw, unharnessed, and untamed. It is about rage and or passion. If you'll pardon the oxymoron, most death metal could be described as emo with feeling or as a musical psychosis. It has a primal appeal that can carry its fans, and it can carry messages with which I don't agree, such as hate, quite well.
But, as others have said, different people have different tastes. Fans of Pop music and fans of Death-metal may not understand how anyone could possibly like your favorite type of music. But, to each his or her own, as long as I don't have to listen to it at full volume!