In almost every case that I can recall it's been a result of a company having cash flow problems, often preceding bankruptcy. The article mentions that interest rates were high in the early 80s and it allowed AA to expand. They've done well to get away with it for now. Or maybe that's just a function of the cost being significantly high such that the market is small.
In the 80s in Australia there was a chain of health clubs that offered a life membership... shortly before going bankrupt.
This scheme has a number of problems:
1. Why offer frequent flyer miles at all? Those are to incent you to fly more but you can fly all you want anyway. I guess there's the option of giving them away but really you shouldn't get any;
2. Booking flights you never intend to take is obviously a problem. AA staff were complicit in that however;
3. An alternative would be to turn any ticket you buy into a first-class ticket. Free anything creates market distortions. It's nearly always better to have someone chip in something to incent the right behaviour; and
4. Life memberships are silly. If they want to attract the business flyers they were talking about it should be an annual charge.
AA are potentially looking at these people costing them money in the wrong way too. These people are essentially AA ambassadors who have paid for the privilege. How much does AA spend on marketing? How does it compare to the cost of these AAirpass holders? I bet these people otherwise sing AA's praises.
Also, what is the fill rate on first class seats on flights? I think part of the point of first class seats is they don't fill up giving premier passengers the ability to buy tickets on short notice. If so, it's incorrect to view each seat taken by an AAirpass holder as a seat not hold (in much the same way as the RIAA/MPAA view every song/movie downloaded as a one not sold).