Because it is the coolest thing in the universe to them. And they actually think cute chicks are finding it cool and other guys who aren't old, fat and too lazy to shift are dieing with envy.
Those wiggers who have cars that shake apart with the base from their stereos will soon be keeping the doo rag but turning in the stereo for a Harley, Snoop Dog for Bob Segar and their falling off the butt pants for assless chaps. Same guy, different stage in life.