The SWA meltdown from what I can tell is caused be a few different things combining to form that perfect storm. First is the storm, and that was amplified by the way that SWA operates in the point to point manner. They have no way to quickly rebuild the airline schedule after their planes and crews are scattered to the four winds by diverts caused by the storm. The hub and spoke airlines have that ability. I can only speak about Delta, but after the NWA merger, we went from 4-6 days to rebuild things to something like 3 when a major IROPS (irregular operations) occurs. When you move 100 million people/year, that's significant.
Another thing is that (apparently) SWA didn't spend much on IT upgrades. (that's anecdotal) That seems to be fairly typical of airline managements because it isn't sexy and you don't need it until you need it. But whoa Nellie when you do, you really do. SWA is finding this out the hard way. We are at Delta, but it is at a disgustingly glacial pace.
Somebody mentioned something about pilots leaving for greener pastures. While some junior pilots have left for DAL/AA/UAL, money is not the reason that they have. Some of the early SWA pilots retired multi millionaires by the time you factored in their stock that they got. Those days are gone though. Usually young pilots leave because of basing options and QOL issues. I had no desire to work there when I was looking for an airline job because they only fly 737s, and after 6 years of that at DAL I had had enough and confirmed that I made the right decision. I like my ultra long haul international thing. So while this was exacerbated by 'staffing', it was mainly because they were out of place, and the existing SWA IT didn't allow quick rerouting of those crews.
What I find comical about the whole thing is the outrage shown by the politicos. Bootyjudge is gonna get to the bottom of this I am sure. Heads will roll (not) and this industry will go back to being vilified for something that started with an act of God. please don't take any of it out on the front line workers though. It isn't their fault. We can only work with the tools management gives us.