> Not sure if you're doing this intentionally
Don't say things like this. If you have a problem with my argumentation, then just say it; don't couch it in weasel words.
As it happens, I addressed the assertion that people are different. Of course people are different, between individuals, between cities, between regions, between states, etc. You then proceeded to refute that very point, so I'm not sure what your thesis is. Is there a vast, shared culture or not?
Well, obviously, I say there is.
The word 'culture' doesn't dictate that everybody has exactly the same mentality, a mistaken line of thought which is very sharply indicated by your assertion that people from a small Idaho town wouldn't 'agree' with more than two of the highly general potential cultural artefacts I listed. People don't 'agree' with cultural artefacts; they participate in them, their world views are informed and shaped by them; their ideas of right and wrong, correct and incorrect, acceptable and unacceptable, healthy and unhealthy, proper and perverse, are all developed by cultures of all sizes: from the micro of the family, the neighbourhood, and the city to the macro of the state or the nation.
Whether all or even the majority of Americans are adherent to the full sum of a describable "American culture" is not the question, and it was never my thesis that it was. If I made any assertion, it's that Americans, as a whole, still adhere to at least some of the tenets of some overaching American culture, something distinct enough that it could be identified by outsiders, taking an etic point of view, as unmistakably 'American' when sufficient cultural artefacts become apparent enough.
It's embedded in the language, in the way people speak, the choice of language they use, their insults, their slurs, their forbidden words, their spelling; it's embedded in the way they interact with others, the space that is kept between interlocutors, the way that strangers are treated, the relationship between a manager and his or her subordinate, and what constitutes professional courtesy; it's in the way that money is spent, the willingness to give a tip, to donate, to accept paying things at retail place, to argue when something costs too much, to seek reparation when overcharged, the wherewithal to demand to see whoever is in charge; it's embedded in manners, the use of 'please' and "thank you", the offence caused to people from other cultures who use 'please' and "thank you" in different ways, how people should address each other.
There are so many more aspects of culture that I really think you're failing to see because, from an emic point of view, as a participant of the culture, you have no clue that they even constitute your culture.
But even if you could identify them, cultural artefacts aren't items on a checklist, whereby only by ticking 80% or more of the boxes does one belong to the culture.
Think more high for it exists, it's still relatively vast, and it's deep; some Americans might only dip a toe in it, others might be positively drowned in it, and I'd be willing to say anybody who claims "people only recognise internet memes and references from 'The Office'" are more firmly in the latter camp than the former, unbeknownst to themselves.