Cars generally aren’t even that loud when compared to some Harley Davidsons. They’re literally continuous fireworks in the street and will trigger anti theft systems.
This seems like first-order thinking. Sure, it makes people more likely to notice the motorcycles. But it also makes people a lot more likely to hate motorcyclists and be unsympathetic to their plight when considering legislation, court cases, their own behavior on the road, etc. I bet loud pipes have done much more harm than good to motorcyclists as a whole.
For pedestrians... Some people seem to feel threatened or indignant when they can detect that someone is going faster than them.
Anyone going slower than me is an idiot and anyone going faster is an asshole.
Cyclists are physically fit.
Cyclists like to run redlights.
Cyclists are too poor to own cars.
Cyclists are yuppies with expensive toys.
Cyclists are drunks who lost their license.
Cyclists use the road for leisure, holding up people trying to work.
Cyclists ride on roads which are for cars.
Cyclists ride on sidewalks which are for pedestrians.
Cyclists lobby for bike lanes.
Cyclists moralize at gas burners.
Cyclists look dumb in spandex.
Cyclists act like they never do anything wrong.
Cyclists are too loud.
Cyclists are bad because bicycles have two wheels.[1] However, it seems it's not true: https://www.autoweek.com/news/industry-news/a35952569/loud-p...