I don’t think it is Americans in general, just that we tend to have people that are EXTREMELY LOUD AND OBNOXIOUS AT ALL TIMES and unfortunately, too many of their friends are too timid to tell them it is a problem.
I used to have a friend like this. We stopped taking him out to restaurants because he was so fucking loud that people five tables away would be giving him the stink eye and he’d be completely oblivious to it. I think I was the only one who would directly, to his face, say something about it.
Right now in one of my game groups, we have a couple of similar people. One guy is so loud it hurts my ears and I refuse to sit next to him. Then he’ll get a call he has to take and be shouting into the phone while crammed into a small room (a bedroom) with seven other people. No one else can carry on a conversation while he’s on his damned phone, he’s that loud. He’s not my friend, so I haven’t gone off on him (yet), but I have made a few small comments about the volume that have gone over his head and because of that, said some things to his friends about the pure obnoxiousness of having someone who is utterly incapable of using an indoor voice when he’s shoulder to shoulder with you.
On my first overseas trip in 1986 I got the full Ugly American treatement on the bus from the Manchester Airport to the train station. Young and Stupid American Girl, going off about foreigners who come to “this country” (meaning the USA even though we were in Britain at the time) and whateverthefuckshewasonabout. It is people like her who give Americans a bad image overseas.