Is Loud Pipes Save Lives a Moto Cliche that needs to go? 

Another advantage of the louder pipe is you get less idiots walking out onto the road in front of you while wearing noise cancelling earphones. The high visibility vest doesn't work because they don't look for you in the first place. The sound makes them think to look. Once they've looked for you, it doesn't matter if you look like a highlighter or not. We've all heard a motorcycle from inside our cars, saying you can't hear it at all is nonsense. The main difference it makes is you get less people changing lanes while you're in that lane already, even in that half-assed study you talked about they admit the motorcycle was audible in that situation.

I can barely hear them when the car is actually moving. I almost merged into a biker because they were hanging out in my blindspot but I remebered seeing them 30 seconds earlier. I really had to turn my head to see them and then I noticed I could just barely hear their exhaust. Positioning is way way more important. I probably would hear the horn, but the low note of the exhaust is not noticeable at all unless you are already paying attention, in which case it doesn't matter. I only notice it at stop lights when they are standing still. Really stupid imo, as someone looking to start riding.

The volume at which people like my wife listen to music you are not getting through with loud pipes until you are 10m away from their car

Loud pipes lead to rider fatigue wich is deadly.

I disagree and I'm living proof, having experienced car drivers not being aware in slow traffic that you are sharing the road to. I'm not talking straight through race pipe noise, just sound that wakes drivers up over the sound of the kids screaming in the back or their favorite dance tracks