I also think people expect every airline to be the same. For example, if they flew for all of their life with American like I did, then you would expect to get the same treatment with another one regardless what you pay because that is what you have come to expect.
I, for example, flew with JetBlue for the first time after flying with American ever since I was a baby. Fortunately, my experience was very good to the point, I always try to see if there is a JetBlue flight to my destination.
But if I would have started flying with JetBlue and then take a flight with American then my experience would have been much different. Older aircraft, almost no leg room, barely visible TVs etc.
It has always amazed me that people complain for paying $200 for a flight that could have cost them twice as much if they would have gone in a car. And not only that, but expect world class service from the cheapest deal around. Got delayed? things happen honey. Your fault for booking a flight the same day as the concert. Its like people arriving 30 minutes before the flight at the airport and complaining about missing the flight.