That's what bikers tell people so that those people stop calling them names. Doesn't mean it's true. The real reason bikes or cars or trucks are modified to have loud exhausts is because the driver wants to draw more attention to themselves for purely cosmetic reasons. If safety was a priority, they would leave the exhaust stock and just not ride in blind spots, not weave in and out of traffic, keep to the speed limit, and generally drive in a predictable fashion.
>has to drive it like that for a week (who vastly outnumber people with loud exhausts)
This is also not true. How would the amount of rusted cars without a muffler for one week outnumber the people who drive like that permanently? The people who either drive without a muffler or who have a modified muffler? For the entire life of the car?
The best way to avoid listening to loud exhausts is for insecure assholes to stop modifying their muffler.
Don't get me wrong: the majority of motorcycle riders are responsible, respectful road users who ride quiet machines.
But a small minority seem to want to create as much noise and distress to others as possible. It's not about safety ("loud pipes save lives" has been thoroughly dis-proven by statistics), it's about appearing aggressive and macho, and perhaps compensating for the rider's own personal problems.
As for a car who's "muffler rusted off"? Should not be driven until it's fixed, period.
Loud exhausts on bikes basically a natural reaction to the improved sound deadening and deeper seating position over time. Vehicle changes have caused a reduction in situational awareness for what's going on beside you and bikers toss on loud exhausts because they notice a correlation between a window thumping exhaust not and not getting merged on top of. While I prefer a quiet exhaust (because stupid people think loud = driving too fast) I wholly understand why motorcyclists want people to know if they are in their blind spots.
Your big brother camera idea sounds like a great way to screw over everyone who's muffler rusts off and has to drive it like that for a week (who vastly outnumber people with loud exhausts in terms of vehicle miles). They like the noise even less than you do (they have to spend more time with it) and piling on doesn't help that. Vehicle noise isn't really a big enough problem to warrant more government involvement than already exists.
The best way to avoid listening to loud exhausts in residential neighborhoods is to not have unnecessary stops/speed bumps to "control traffic speed" (or whatever other justification the HOA cooks up). They just make people accelerate between them.