Why do people find metal and other music, that can not be understood, as attractive?

One could say that subjectivity is what makes art so fascinating. While metal may resonate with some, it may not with others. In regards to understanding, I suppose there are facets of different music genres some folks could have trouble understanding. (Screaming in metal, body movement in hip-hop, etc.) These sorts of things can hopefully be explained by respective fans of different genres.