If all cars have it, arrogant pedestrians will just step off the curb at will, pleased to have impeded you and spilling your coffee. Carjacking gets very easy, too.
BTW, back in my days as a pedestrian I found that enough drivers pay no attention to pedestrians ~ or at least SEEM to pay no attention ~ that it's pretty dangerous to attempt to cross at any busy interesection even if there are full pedestrian lights.
So I'd pick up a rock ~ and those people who don't pay attention would pay attention just like the mean dog who thinks it's his job to bark and snarl at everybody.
No idea what I'd do with the rock but there'd be drivers sitting there, seething, snarling, look at me with evil eyes, and sometimes screaming.
Pedestrians are not, by law, in your way ~ you are supposed to take care to AVOID hitting them ~ these brakeing systems will help you.