Because i noticed whenever i am out and about and sitting in traffic this car or truck always pulls up playing rap that i can hear clearly and the rap is mostly about busting a cap up someone's butt and such, instead of proper music like heavy metal or rock.
There seems to be a mindset that believes that one can compensate for low quality and lack of artistic value in
“music” by playing it louder. Since
crap is the very lowest form of auditory garbage, it therefore follows that those who choose to listen to it are the ones who think that it needs to be played most loudly.
Your heavy metal or rock are really only a slight step above
crap, hence a preference on the part of those who want to listen that garbage, to play it loudly.
Real music does not need to be played at absurd volume to be enjoyed, and, in fact, doing so generally tends to detract greatly from it.
For those who are unfamiliar with the sound of real music, I present this example,
Serenade to Music by Ralph Vaughan Williams.