Why on Earth do MetroCards expire?

My daughter and I went into Manhattan on Saturday for an acting audition she had, to get accepted into the drama department at Marymount Manhattan. We took the route we usually take, driving to Jersey City. We parked in the Journal Square PATH station and went inside to catch the train to 33rd Street. I had grabbed a couple of MetroCards off the top of my dresser before we left, confident that there was enough money for the two of us to go to the city and back. When we got to the turnstiles and put the cards in the slots, both screens turned red with the message: Card Expired!

Why would a card expire? I had given the Port Authority my money already and had occasion to use the card for awhile, so why should it magically expire? There’s nothing to go bad about the card so there’s no reason for it to expire. According to the New York Times, the MTA made about $500 million over a ten year period ending in 2010. That’s a lot of money. They say the cards generally expire about a year after you get them and there is a process for getting your money back through the MetroCard Customer Claims Unit, but few people go through the hassle. Again, why do the cards expire at all? The Port Authority got however much was left on the cards, plus $11 for two round trips on a new MetroCard. Nice racket.