Whizbang Dustyboots
Gnometown Hero
Well, it's not not what it's getting at. I think the Star Wars cantina effect present in so many D&D games is due, in part, to the fact that D&D is created by a nation of immigrants where it's always been common to know people who speak different languages than you do at home, where the student at the next desk in school prays in a different way than you might, and where -- since modern restaurants became a "thing" -- it's routine to go out to eat the cuisines of wildly different cultures.Edit: As far as that goes, you could write a thesis arguing that the entire style of D&D's polyglot approach to fantasy is quintessentially American, but I don't think that's what the thread was getting at.
That kind of heterogeneity isn't uniquely American, but it's something America has to a greater degree than most places on Earth. (That said, D&D coming out of Singapore, which is also a nation of immigrants, would be amazing, but different in many other ways.)