oh oh oh! It's prejudice time!
Every country has it's own. Personally I'm dutch, so I must be cheap and annoying. And soon I will meet my American sweetheart, but she must be stupid and stubborn, right?
I think the problem lies in that too many people go somewhere and treat everything as if they own it... if you're a tourist, then you're a GUEST in the country and should treat everything with respect, in return you should be treated with kindness and generosity.
And guess what, if you act like you're a guest, 9 times out of 10, you actually WILL be treated with kindness and generosity. If you at least TRY to speak the countries language, most natives will look kind on you and help you. If you flat out refuse and try to talk to the natives like you talk to your fellows back home.... then I don't blame him for giving you directions to Timboktoe instead of the local tourists office.
Americans just have this more often because the majority have never been outside their own country.
The only exception to this is if you are a tourist in your own country, and even then it's always to good idea to respect and be humble.
My $0.02 anyway.