It's not at all clear that adopting bits and pieces of Southwest's approach would improve the financial performance of another airline. Some of the features only work because of other features.

As an example, Southwest does not charge you a change fee. You just pay the new fare using the old funds, plus any increase in fare. To make this work, Southwest has a harsh standby policy. If you want to take a earlier flight than you booked, you need to pay full unrestricted fare, which may be twice your original ticket price. Even if you're only going half an hour earlier. This standby policy is the flip side of the no change fee coin.

Another point is that an airline's policies need to mesh with customer expectations of that airline. It can take years to change expectations, and airlines cannot afford to lose money that long on a change. To a large extent, all companies are stuck with current policies and will not benefit fast enough from making the policies more generous. Alas, this is even true of loyalty programs.