Believe it or not, this was actually an improvement over the answer I received from the customer service representative. His answer was "because a memo came down from Corporate."
I really wonder what's wrong with people. My boss attributes much idiocy to innumeracy. I know that I myself am mathematically challenged, however the folly of trying to attract and retain customers by implementing an industry's worst practices makes me think that innumeracy can't possibly be the only problem.