You seem to have a real issue with Americans in general. It'd be just as wrong to say that all New Zealanders are mocked because of their accent, and they should try not to sound so silly. Do some people in other countries have beef with Americans? Sure, and I've run into plenty in Europe. But I've far and away run into more folks that simply don't care and are friendly, or are keen to talk about the U.S. Might be worth taking a hard look at your prejudice.