I think it is inappropriate in an interview situation 100%. If you can’t hold your tongue on some slight discomfort or perhaps talk about in a more diplomatic way (eg not singling out the specific person but rather just stating your upset at the interview being delayed) how are you going to react if clients/customers make you uncomfortable on conference calls? Are you going to be tactful and polite, or are you going to be direct and rude to them?
Obviously I don’t know the role you were going for etc. this is just an example, but I think doing this gives a bad impression that goes beyond just whether that specific person was irritated for you calling them on their lateness
I’m not in the US but yeah the country has always had a strange relationship with law and order, at least from an outside PoV. The Kent State massacre is always one that sticks with me as particularly messed up.
I don’t think the USA is necessarily changing at all, this is what it has always been the whole time