I'm not so sure that "normal people" don't also book away from the USA carriers when they travel internationally. Many times a year, "civilians" comment to me about how well they were treated on various foreign carriers. Sure, these people don't travel that much, but I think many of them will look to take the foreign carrier on their next trip.

Also, the "flyertalk business" for these foreign flights is huge. Even if we're a small percentage of the population, we're a very material percentage of airline revenue. Anyone see the stats: I'd guess 5% of Americans take 50% of int'l flights, and that 1% take 20%.