Postmodernism has been en vogue in the USA since the late 1950's. You only need to look to American literature since then and you'll notice much of what is considered the "most important" fiction is Postmodern. Which means it is cynical, ironic and skeptical of all the things you associate with the French.

This is not a fringe philosophical concept bound to popular novel's either. Look to the background of villains in mainstream super hero movies, to our politics (many call Trump the first Postmodern president), and the drive to be "authentic" in every aspect of the self for reasons of self promotion in some kind recursive cynical loop which other view as a perfect specimen of our contemporary irony, nearly perfected!

I'm not an expert on French culture or any culture per-se, but perhaps Americans (of which I'm one) do have a more superficial embrace of sentimentalism and a less critical approach to hero worship and "getting rich" and maybe it isn't driven by cynicism as much as naiveté but that's only one aspect of the culture as a whole. Even still, I'd argue most people are driven by the Postmodern philosophy wether they know it or not; are more cynical then they even know and skeptical of our institutions (universities, churches, etc) on one side or another.