You are referring, of course, to this excellent (and somewhat frightening) article: http://philip.greenspun.com/flying/unions-and-airlines
There was an episode of the podcast Planet Money where they claimed that the American Airline industry has, as a whole, actually lost money over the course of its existence. As in, overall, net financial loss.
In this case, airlines are a business designed not to have runaway profit. The unions are very powerful. They know how much money the airline is making a demand large percentages of it. They leave a nominal profit for key investors but shareholders as a whole are regularly left out. In fact, if you look at the entire history of commercial flight, the industry is break-even.
That's not a fluke. If costs were higher, unions would get a smaller cut. If costs were lower, unions would take more.
Philip Greenspun has some great writing on this, as well as the old, shortlived but fantastic Enplaned blog.