Scott H. Haycock
Steel woodworking blades of this type (no set) are hollow ground on the sides of the blades just for this reason. The thickness of the blade is reduced between the teeth and the center of the blade to eliminate the blade rubbing against the work.
I agree with both your points. But I'm saying why not minimize or eliminate the problem by lessening blade contact by having set on the teeth.
It just doesn't make sense to rub plastic on a spinning steel surface, which is what happens when there's no set on the blade teeth.