Why do people press the Crosswalk on at intersections repetitively?

Just to let all who didn't know, it's the same thing pressing the on 1 time as it is pressing it 100 times! The stop lights and cross walk signals are on a regular timed basis and once the cross walk on has been pushed the first time, you've let the light know to change for pedestrian crossing! No use in hammering on it with your thumb, unless you want to look... (something that rhymes with thumb)