If loud pipes save lives, electric motorcycles are deadly. I have walked in front of an approaching hybrid car because I didn't hear it coming. Thanks to the quick reaction of that driver I didn't get hit. So think of what it would be like to be riding your silent electric street bike on a city street. Not hearing your approach, a pedestrian steps off the curb right in front of you.
Fans of electric vehicles seem to not remember their high school physics. It takes exactly the same amount of energy to move a vehicle regardless or where that engegy comes from. It is very likely that the electricity used to charge the battery is generated by burning fossil fuels. Electric vehicles do very little if anything to reduce carbon emissions.
A lot is written nowadays about the future of motorcycling. Some think electric bikes are the wave of the future. I certainly hope they are wrong.