Airlines for years operated under the impression that travelers would pay more for certain benefits. Frequent flyer programs proved that in spades -- so much so that many employers employed third-party agencies to police their employees air travel buying habits, and governments the world over prohibited civil servants from participating in FF programs.

But now airlines are trying to offer less and less, including with their frequent flyer programs. As long as people need to fly, and as long as all airlines march downwards in lock step that might work. But as soon as fewer people need to fly, and/or one airline decides to try to win back some of that "unused capacity" (as American Airlines did in 1984) then it will all fall apart.