Greentext

Big food is kind of a marketing thing in America. Restaurants want to give their customers more " bang for their buck" (or at least appear to), but they don't want to lower prices. Instead, they increase portions. This has lead to a size arms race where every restaurant wants to claim they have the biggest food in town. This is especially the case for burger joints. It doesn't matter to the restaurant if customers eat all their food, since they pay for all of it either way. I'm guessing Americans are more culturally susceptible to this marketing tactic, since bigger-is-better is common here, and hence things have been taken further than in other countries.

This seems to be another case of someone throwing reason out the door for the sake of insulting Americans. There is no way you would be getting "shit eating grins" for ordering a kids meal. And if your large burgers are smaller than a kids meal, you either have very little size variation, or the small would be like a single bite.