Parents need to train their children to understand the nasty reality you describe, and to behave when crossing streets in a self-protective, highly aware stance. Same when walking in car parking lots. Oh, and walking on ped-bike paths shared with fast, quiet, electric bikes.
A pedestrian may press the button to make the beacons flash, and cross within a well marked crosswalk in broad daylight, in a place where pedestrian traffic is high. And an aggressive motorist may run her down anyway.