Earlier quoted context omitted.
Because most people search fares online and book the cheapest ticket.
That actually does not disprove the GP's point. People do this when the price difference is too high, or when they don't know of any difference of value on both options. Currently air travel is a completely homogeneous service. There is basically no difference from one company to the other, so it makes no sense not to go with the cheapest (even then, the flight schedule matters). That is not reason for a company to n…
Southwest has a pretty loyal following since you can "refund" a ticket for Southwest credit good for a year.
Alaska and Delta don't charge for bike fees (they're just priced like ordinary luggage).
And aside from maybe 1K members, I don't know anyone who enjoys flying United.