The people that would really benefit the most from this are people who would use it a lot on the same airline (read: business travelers milking those FF miles),

The people that would really benefit the most from this are people who would use it a lot on the same airline (read: business travelers milking those FF miles), i.e., the people to be most noticeable for the airline and the people with the most to lose from being discovered. They're not that worried about regular folks doing it once or twice a year.