America is kind of like the jerk team in kids sports movies.
You guys are big, rich, confident, and usually come out on top. Even when the individuals who do win happen to be gracious and decent, there's still the fact that your nation, as a whole, is a powerhouse machine that seems like the asshole to almost everyone competing against them. It's almost impossible to be on top and not have haters.
Is this the argument for Canadian gracefulness? :lol