As I have posted many times, because of past instances affecting other Flyertalkers, my specific choices for airlines and routes and the reasons for them are private.
However, I will say that CO has lost substantial revenue from my firm (%50) because of this change.
But this has little to do with the subgect at hand. We are not discussing a CO policy, but a policy of all US airlines. Bait and switch and whether or not it's truly fair or leagal, or should be challenged.