It's my understanding that the majors make a ton of revenue off the checked-bag fees. That's why they do it; even though it encourages people to carry-on, and that decreases plane utilization (longer turn times), it still makes them money.
(It also encourages airline loyalty. Fly 25k miles on one of the legacies, and now checked bags are free. I stick with the legacies because of the great loyalty programs and the ability to use the same airline domestically and internationally. It is also nice to have an assigned seat.)
(It also encourages airline loyalty. Fly 25k miles on one of the legacies, and now checked bags are free. I stick with the legacies because of the great loyalty programs and the ability to use the same airline domestically and internationally. It is also nice to have an assigned seat.)