10mph is fast from my pedestrian point of view on the sidewalk

In California I've seen people do it without stopping, they would have been doing about 20.

Of course, that would have been illegal, but I think right on red laws encourage it.

The article seems to indicate that pedestrian collisions are common during this maneuver, even if deaths are unlikely. Given that collisions are costly (injuries, insurance) and damaging (make people afraid of streets, make neighborhoods less safe for people to inhabit), it doesn't seem irrational to try to reduce them, deadly or not.

You haven't seen Florida drivers turn right on red. Also, is death the only measurement? Would you be happy to be paralyzed or maimed?

There are negative impacts other than death - especially in the United States where medical care is triple the cost of the rest of the world and we have very limited provisions for long term care or disability support. Drivers routinely make a right turn on red at 20+mph in most American cities and while trauma care is efficient enough that you probably won’t die, there’s a good chance it’ll have life-altering consequences.

Another thing to consider is that 20 years ago, you’d be more likely to go up on a cars hood. Nowadays with the average height of vehicles, I’d imagine that more likely than not people will be going under vehicles that don’t stop right away.