Another counter to the "loud pipes save lives" argument is basic human nature - to drift towards what catches your attention, also neglecting to notice what else is around you as you do so.
I dunno how many
times some random car endangered me and all those around me just 'cause they were starin' at my bike instead of paying attention to their driving (and my bike is as quiet as you can make these things) - this is completely at odds with the commonly held opinion that bikes are dangerous because they're "invisible" - while there's some truth to that, I'm far, far
happier "unseen" and left to my own devices than the center of attention as they neglect to notice the car pulling out in front of them, drifting towards me - or even drifting into the oncoming traffic.
It happens to me alla time grrr "Don't lookit ME - lookit the bedanged ROAD you tool!!!"