Here’s the short answer: there not enough real competition. Last week’s trip to San Francisco made me question why on earth would United be so successful in this area if it offers service that is inferior to Alaska, JetBlue and even Delta. According to my cursory examination of DataSF information, United has 31 flights into San Francisco. From what I experienced, most of the flights are full. For as long as United dominates SFO it has no incentive to offer better service. It might compete on price, but a regular economy on jetBlue, Virgin America/Alaska is better than what United offers on its “Premium Economy.”
My next trip to the West Coast will only be on United if I can get a cheap upgrade to business otherwise, the top contenders offer much better ways to go across the country.