And, Four Seasons?
My guess: the tres upscale Seasons and Ritz figure they wouldn't derive much benefit from mileage programs. Although some business travelers stay at the upscale joints, most corporate travel policies top out with the Marriotts, Westins, Hiltons and Hyatts. I do notice quite a few legal and medical conferences at Seasons and Ritzes, though. Those lawyers and doctors sure know how to live.