Joe, just mark that up to two pelotudas talking, not because they are Argentines or because they are criticizing the US, but because they are young and think they know it all. A teacher at my school had a bumper sticker on his classroom door that said "Hire a teenager while he still knows everything." Have truer words ever been spoken. Those girls are not teenagers and should know better, but they are probably still teenagers in their maturity level. That kind of thing does piss one off, though, because it's just inappropriate for the context and the sense of superiority that's lies behind it. There are many legitimate criticisms of the US and ways in which Argentina is superior to the US, but their intent was not to inform, but to try to be arrogant and superior. You should have finished your conversation with them with the question, "Nacieron pelotudas o las educaron así?"