So other than being stoned out of their minds (bad enough, granted), there’s no other reason? Like, maybe the sort of person who would alter their engine to the point where it can be annoying from several city blocks away might also be the sort of person given to reckless and moronic behavior on the open road?
Maybe not moronic behavior on the road but it is somewhat moronic nonetheless. I have noticed in my 50 plus years of riding that a good many of the (extremely) loud muffler harley boys tend to act pubescent, regardless of their age.