well, at least there wont be any stupid loud harleys in an electric future 
Unfortunately motorcycles are loud for a practical reason. Most motorcycle accidents are caused because the person in a car didn't see the motorcycle, so people modify the volume of their bikes so even if you can't see them you know they're there.
The loud muffler is only heard when the motorcycle is moving, so instead of having to endure 5-10 seconds of an accelerating motorcycle when the light turns green, you’ll have the pleasure of listening to a deafening loud Willie Nelson or Toby Keith song while you’re stopped at the red.
ha! i was wondering if someone would say that! that is a load of crock! no offense, dartful. have you never had the ---Cleveland steamer--- scared out of you when a stupid harley roared past your car? you had no idea it was there until (from the riders perspective) it was too late. you just wont hear it while hes gaining on you (while speeding). the sound hits you pretty much when they are next to you. if anything, it could be more dangerous. some volvo driver might jerk his wheel when that wall of sound hits and crash into the harley!
if bikers are honest, they make them loud because it sounds cooler. interesting case in point- i occasionally see groups of bikers and one or two of them are riding buells. funny thing is, the buells didnt have a modified muffler. i have test ridden a buell to 200 km/h (shhh, dont tell the dealer) which is plenty fast for a harley. thus no one bothers with buells funky under-frame can.
we are talking, after all, about the same people who deliberately take off their indicators, sometimes dont even have fromt brakes (some choppers and bobbers) and wear those retarded little pudding bowl helmets that arent approved. safety conscious indeed...
besides, whats safe about hearing a bike one SUBURB away?
latest statistics here have shown what we all really know deep down- the majority of severe bike accidents happen to males, who were speeding, and were also drunk/stoned. a loud pipe would not haved saved life in those cases

i love the sound of engines. but noisy bikes are best appreciated at a racetrack...