not sure the safety argument has factual support; the sound would need to project forward from the motorcycle, wouldn't it?

hmmm, if I have to hear the noise, I would like a requirement that it blare forward! (so I can step into the crosswalk)

If noise made your bike safer, you’d get an insurance discount. People say such things so that they don’t come off as sociopathic, not because it is true. Don’t parrot them.

So should every pedestrian have a blazing siren on their head?

Pedestrians should not be on the road.

No, cars should not be on the road.

Roads were built for cars.

That's not actually the case in many places in the US, they were forcibly taken for cars in the same way electric streetcar systems were taken from us:

> Before the American city could be physically reconstructed to accommodate automobiles, its streets had to be socially reconstructed as places where cars belong [..] Until then, streets were regarded as public spaces, where practices that endangered or obstructed others (including pedestrians) were disreputable. Motorists’ claim to street space was therefore fragile, subject to restrictions that threatened to negate the advantages of car ownership.

https://mitpress.mit.edu/9780262516129/fighting-traffic/

Coming up with a fact that roads existed in the ancient times is not a gotcha. Most of the roads today did not exist back then. 99% of the roads I have driven on did not exist before cars.

Crosswalks

Crossing the road is different from what is being discussed which is riding along side cars.

safer for whom? My windows only rattle after the motorcycle has driven past, they don't project the noise ahead of you nearly as much as you think they do.

If you are riding on the highway going the same speed as other cars, it is often hard for them to see you, but if they can hear you they know you are there. It isn’t about driving past.

Which is the same reason every biker with loud pipes wears a full high-vis outfit.

Or maybe they're just assholes.

Most of them are assholes, but that doesn’t mean it’s not safer to be louder.