Up in the Air director Jason Reitman explains to Oprah,

Jason Reitman: I think it’s a combination of things. One, it’s the thing that you first brought up—it is a community. If you look at a website like FlyerTalk.com, for example, you will find a group of people who have banded together in their passion for this kind of lifestyle of living continuously on the road and who have an unusual definition of the word home. It’s a group of people that are just as comfortable if not more comfortable living in constant flux—hotel to hotel, airport to airport—who get a sense of thrill from being surrounded by those destination boards knowing that they could suddenly be off to any city in the world. People who live by their daily itinerary. And I think one of the reasons they have this not only passion, but indignation, is that there’s been enough movies like Planes, Trains and Automobiles, there’s been enough news pieces and articles on the frustrations of travels. It’s an easy enough conversation point, so if you love travel then you angrily defend it.

(Hat tip Randy.)