why is it that "rock" and "metal" songs are more about fustration of the protagonist or disappointment?

Question

i mostly hear words "tension""failure""heads explode" in these songs

Answer 1

They´re not all like that, but yeah i know what you mean, most of the songs are about pain, dissapointments and all those deep sad feelings we have inside us. The reason is that rockers who sing these songs are "lettin go" off it all, the frustration, the agony, they´re just venting and lettin out all their anger through the words of a song. Of course the jamming electric guitars and everythin adds to the atmosphere of it all aswell.

I hope this helps. :)