What you saw was a college student in a suit taking a weed break. Besides, I'm much more comfortable supporting a character named "Grimace" than one named "Smiles" or "Giggles." Maybe its meant to insinuate that McDonalds will make one grimace if one eats the food; I personally find it the least appetizing of all fast foods (except maybe A&W's, trashy) and would rather eat somewhere else.
Though I can't demonize the place becauase it doesn't suit my tastes. How fair can that judgement be?