I think America is too vast and diverse to be described that way. Your description doesn't at all describe the no-gaudiness humble-behavior expected in most white, mid-western communities. Utilitarian individualism doesn't at all describe the vast swarth of America's most religious peoples. E.g. The Amish, the Johovah's Witness, Fundamentalists, Mormons, etc.

What you're describing is an extreme of American popular culture, which is a small, biased selection of the American population. I'd be interested to know if there's any evidence that these traits are higher in the average American than in other countries. For N=1, I am pretty quiet, calm, spend plenty of time meditating, and don't really care about superficial appearances.

Where are you getting this from? Movies?

That might explain this constant commentary I see from our European friends describing America with exaggerated stereotypes that bear little resemblance to reality.

I see it too. I suspect non-Americans consume a lot of US media and as a result feel sufficiently educated but they look just as silly and ignorant as Americans who think Europe is a country.