Don't blame Southwest. Blame the FAA and Atlanta for letting Delta buy FL's excess capacity at ATL. Southwest was never going to make ATL a focus city. Delta is just too strong there. But an upstart like Spirit might have given it a shot. ATL has no business being the world's busiest airport. It isn't a financial hub, or in the center of the country. The city is too small, as well. Delta just decided to make it its fortress. They could just as easily have done the same in Birmingham (and nearly did).