The reality is that for the most part, the legacies will retain their loyal frequent fliers. Those mileage points are important.
It's the non business travelers, the people who fly 2 trips a year that will shift down to Frontier. But if you look at what kind of companies do well during recessions, its always the ones that cater to low costs. That's frontier. And, we are in a position to remain profitable longer into a recession that the big boys with their substantially higher operating expenses.
During the last recession, the ULCCs grew. In Europe, the last recession completely changed the market. Now Ryanair, EasyJet and Wizz dominate. In the US, Spirit took off. I'll repeat something I mentioned earlier in this thread. During the last recession, two of the best performing stocks were McDonald's and Walmart.
Also, just to poke a little fun; if you are looking to NetJets customers to fill your planes during a recession... you're going to have a bad recession. It's hard to fill 750 mainline jets with the .1% of the population