Glen, have a look at
this Wikipedia article. There are several studies which show increased number of accidents when comparing quiet hybrid cars to "normal" cars with internal combustion engine. As the increase in accidents only happen at low speeds (<20km) the regulation to make noise also only applies to such speeds. I would call it common sense and not an over-regulation.
Also it is worth mentioning that Japan had such regulation since 2010 and US brought one last year (to start in September 2020).
Go for a walk at your shopping centre car park and pay attention. If the car next to you has its engine off most of us will not even bother looking to see if it will start reversing into us. It is not something we would expect. But if you can hear the car running I bet nobody would just blindly step behind it.
edit: This was a reply to your post which disappeared while I was typing???
An EV with other traffic is a bad argument and will work only if there is a continuous flow of cars on the street. Which in reality never happens. And what will happen when we have more EV cars on our streets, when the old noisy cars become a minority?