I think your prejudice is blinding you to something that makes good sense in context. I don't expect to change your mind, or even that I could, but it seems odd to blanket denounce a behavior present throughout North and South America on such a weak premise as "we don't do it here." How can you be blind to the use in communicating shared histories in an increasingly multicultural society? I think you'll find that the same behavior is present in many primarily immigrant nations. The US, Canada, Australia, Brazil, and others. It's just a shortcut we make because those categories, however arbitrary, mean something to us and allow quicker sharing of information. "America bad" is such a tired argument. Americans may have a generally high opinion of themselves, but I think you'll find similar behavior in the defensive nature of those that belittle them as well. Humans are humans wherever you go. Step down off your high horse and recognize that maybe a behavior that naturally develops among hundreds of millions of independent people from different backgrounds entirely might be due more to its intrinsic value than some bizarrely specific American thing. Because it isn't. Americans are just an obvious example of it since they have such an overwhelming presence online.