Idiot-proof WALK sign

I sold Girl Scout cookies on Market street for three days.  I cannot help but notice that my fellow citizens are, by and large, knuckle-dragging troglodytes without the ability to spit directionally, not walk into a pole in the middle of the sidewalk and not cross against the light.  Apparently the Department of Public Works has figured this out also, and erected the WALK signal buttons shown below.  I can only wonder why they think they need to save the lives of these drags on humanity’s improvement:

I find the assumption that the target audience might be able to read overly generous.