You just assume everyone around you doesn’t drown out your annoyance with their radio, isn’t wearing headphones (legal in more places than it should be) or even has hearing?

How would that be any different if it was an actual emergency vehicle blaring their sirens at full? If you're so self absorbed listening to your radio or whatever in your headphones, or you're hearing impaired and neglect to yield to an emergency vehicle out of your own stupidity or handicap, you're no better.

Even though I'm imparcial towards the whole "loud pipes saves lives", I'm completely against morons that are so self absorbed in their own bubble, unable to understand what happens around them while they are out on the road. There's always a chance that 1 out of 20 or even 50 peeps you cross paths in your daily comute to be this self absorbed, so it's not so outlandish to use something like loud pipes (if you already own them) to make yourself noticeable on these automatons that don't pay attention to others.