There is statistical evidence to support the argument. Direct from the 2008 inbound travel report from the ITA Office of Travel & Tourism for the United States.
Top 10 Countries of Origin (in order):
Canada, Mexico, United Kingdom, Japan, Germany, France, Brazil, Netherlands, Italy, & Ireland.
Top 10 US cities of entry (in order):
New York, Miami, Los Angeles, San Francisco, Chicago, Honolulu, Atlanta, Washington DC, Orlando, & Boston.
Because of major airline hubs, I realize that a few of these cities are probably ports of entry rather than final destinations: Atlanta comes to mind. But, I'm willing to wager that in most cases the city of entry IS the final destination for most international visitors.
I admit that it is a pet peeve for me. It's because I live in the central part of the United States. The part that Americans themselves call "fly-over country".
It is frustrating to be a traveler who loves to visit other countries and loves nothing more than to have visitors from other countries visit my town. But, getting international travellers interested in visiting my part of the country is an uphill battle. HECK, most Americans who live on either coast aren't interested in visiting St. Louis, so why should someone from London, Toyko, Berlin, Paris, Rio, Amsterdam, Rome or Dublin be any different?
I don't have an answer. I just feel better getting it off my chest.