The reason is because people doing that would be able to acquire status for a far smaller amount of money than just about everyone (even FT'ers) actually achieve status for. Me, for example, would simply book a series of inexpensive SJC-JFK flights on AA, and POW! I'd have a lot of miles and status for cheap (since that's a fairly cheap market).

I believe, in a sense, status IS for sale -- if you are bandying about enough money -- for example, corporate travel departments negotiating new contracts often get status for all their employees...even those who won't be flying much.

Steve