At Freakonomics, Arthur Frommer - yes that Frommer - answers questions from readers about travel. It's all a good read, but I was especially interested in his answer to the question: "As the dollar continues to fall against the euro, why aren’t more Europeans traveling to America?" In part, he says:
Because of the psychological, bureaucratic, and political barriers that we have erected to hinder their travels here. In many of the countries that don’t enjoy our visa-waiver program, it takes three to four months simply to receive an appointment to apply for a visa. Once would-be travelers finally get inside one of our consulates, they are questioned about personal characteristics having nothing to do with security or terrorism, but rather with the possibility that they will overstay their visas and become illegal immigrants. One tour operator handling incoming travel from Poland recently said that half of the people he wishes to send to the U.S. are turned down for visas because they are young, single, without property or homes that they own, etc., and are thus more likely to stay in the U.S. illegally.
When people do travel here, they are treated like criminals upon arrival at customs, or, at best, received with cold discourtesy.