Flour bombing is almost always a part of an organized event, like a pancake breakfast, and all of the participants know at least a little about aviation and participate willingly. If you are out in a watercraft just enjoying the experience and, without any warning, a general aviation aircraft comes zooming over you at 50 feet or so and folks on another boat are waving at the plane, you might think "I'm writing a letter to the editor and to my congressman as soon as I get home...those little airplanes are just noisy toys for rich people, and maybe I'll sign that petition to close the airport!" That's the difference: perception.
I've been involved in this industry since 1960, and the number of pilots who figuratively shoot themselves in the foot by annoying the general public never seems to diminish.
