Interesting this came up. I had a meet and greet with one of our companies execs who happened to be from Germany and he talked about this topic a bit today. He brought up an interesting point, that English as a second language speakers may come off as rude to some Americans, because they don't know the subtleties of our lovely language, sarcasm on purpose cause we have some weird stuff in there. So we Americans should cut them some slack.
I work regularly with people from Europe so I am used to it. As he described Germans attitudes, I realized that even though my family line has been in the US for over 100 years, I have that attitude lol.
To what Schmoo said about Mexico, I am wondering if they see the have you been to the US as a sensitive question, not just now, but for many years. Our intentions could be pure, but they may not see it that way.