I don't think that's true. Airline executives are, for the most part, the Peter Principle in action. They are in a job way beyond their level of competence and they know it. They don't want this gravy train to end and will do whatever they can to keep it going. This is exactly what Zard was referring to and you see it in a lot of low to medium performing operations, especially in government.
I am sure the idiots running ground ops at this joint were great ramp supervisors.
MBAs may not always be the best choice to run a company (see Boeing), but they have their place in the management ecosystem. A lot of time and effort is dedicated in a good MBA program to examining companies just like Southwest and figuring out what went wrong and how to fix it. Some execs have the right mix of people and operational skills to pull it off, some don't, but a formal education certainly helps.