Americans stock their shelves with "swiss" "american" "jack" and "cheddar" with almost all of them being made in about a week in cheese factory somewhere.
Contrast that with having TWO versions of Cantal, one of the blander AOC cheeses, in every cheese case we encountered in France. To say nothing of blues I'd never heard of, and small batch regional cheeses in many supermarchés.
It's all hearsay and conjecture, really, but I think the outsized influence of American chefs is just due to TV culture which is pervasive and consistently unfortunate.