I agree that you can find the ultra nutbag who recoils at the sight of a gun as if they came across a rattlesnake.
However, in general the average individual who feels uncomfortable when they see a 'person' with a gun does not have the same reaction with a uniformed authority figure like a police officer. Hence my hypothesis; that it is the person that elicits the response much more so than the gun.
Perhaps it is just to much of a stretch for me to rationalize how one can fear an inanimate object.