we’re still pretty diverse at a region, state, city, and often even small-town scale

I suspect it is mere laziness. Either in writing or far more likely, in the (lack of) thinking behind that. In the same way in which you cannot extract blood from a stone, so too conversations in e.g. memes@lemmmy.ml are not going to reflect deep philosophical insights.

Likewise believing everything you see on TV, or even bothering to watch more than a couple shows before making snap-judgements. I believe the word you are thinking of is stereotype - "A conventional, formulaic, and often oversimplified or exaggerated conception, opinion, or image of (a person or a group of people)". Again, some may not even believe what they are saying, just using short-cuts in their language, although sadly many seem to have drunk the kool aid there. But, the USA is not the only target there - nearly all forms of argumentation happening across the entire Threadiverse seems biased to me so I've given up nearly all hope of truly rational dialog, on any social media platform (it's possible, it's just so frustratingly rare that I cannot extend my hopes for it forever, it is simply too draining for me to do so).

Can I get that on a throw pillow or cross-stitch?

If you are an oligarch then you can get whatever you want!!! Otherwise, we can get fucked, it would seem. 😰

Don't forget also: people are mad, and disappointed. And that is understandable, as we are as well (highly ironically, virtually everyone across the entire USA seems to feel that right now, making it like the ONE THING that we all have in common? both among ourselves and with our European and Global South and Asian and other brethren and sistren and other). It is emotionally a protective measure to "blame someone else", rather than take even the slightest responsibility for oneself, e.g. for placing too high hopes in the status quo, despite literally all of history, recorded & otherwise. An example could be the mantra "number must go up", which is literally (not figuratively!!) ridiculous even on its face, and yet almost everyone that I've ever met seems to have gone all-in into believing that it would hold out pretty much forever...

(censuring myself here b/c I typed out a political-themed paragraph but according to rule 2 decided against sending it)

It is not just some European users of Lemmy that are stupid - it's me too, all of us! :-P We all have biases in our thinking, sometimes. It is simply easier to see such in someone else than it is in ourselves.