Some customers are better than other customers. Some frequent customers (who pay higher fares) are better than other frequent customers (who pay very low fares). Orwellian? Perhaps!

However, if I pay $198 to fly from PHX-SEA several times a year, I'm simply not worth as much to US as someone who pays $698 to fly from PHX-SEA several times a year. At times, it may make sense for US to deny me the $198 fare in order to retain a seat for a potential $698 customer. Therefore, I might have to fly AS or WN a couple of times per year.

That's the reality of the business. Sometimes I have to "fire" low value customers and essentially say, "Take a competitor's flight!" While we don't necessarily like that, it is the essence of Revenue Management, which says that the airline needs to maximize the revenue of each seat sold -- and ultimately make a profit.