In Japan there is sometimes a button for cyclists/motorcycles to push to get the lughts to change. I assumed this was because there is a sensor in the road to detect cars, but now I'm not so sure.
If the pedestrian was about to get green (or blue) but a car was detected and the pedestrian was forced to wait then that's not fair is it?
We already prioritize cars enough, pedestrians usually have to press a button to trigger the crossing so they're always waiting but cars don't get punished for getting to the lights a second after the sequence starts.
Close to where I live there are a couple of funny examples:
In one place the lights are red by default for everyone. Cars are detected from 100m or so away, so they barely need to slow down. Pedestrians need to press a button and usually wait for a while.
At another crossing the lights are green by default for the bigger road. A sideroad has car-detection that is ofter rather quick. Pedestrians and cyclists need to press a button and usually wait for a long time.
Just because you don't sit in a car it's ok to wait that much longer.
A random pedestrian is just as likely to be helped by a light change as hurt by it. You provide an excellent example of motivated zero-sum reasoning though!