I’ve encountered bad manners from Americans too. Randomly asking for the time on the street with no thanks etc. Must be a cultural thing. Not a patch on the Russians though, and they don’t need defending. That you got a smile off a random bit of skirt for oddly settling her bill does not make up a million other antisocial acts. They do not fit in with the rest of the world, expecting everyone else to bend to their ways, much like the typical Chinese. Planet earth would be better off sans either.