After a certain amount of time ( different for each individual) there comes a point where enough is enough. When the extra cash for doing overtime doesn't compensate for the extra workload that the wife picks up at home, for not seeing the kids as much as you think they need, for being tired and grumpy on your days off as you recover from the circadian disrhythmia. When that time comes for enough workers, and they are thinking of leaving anyway because it's not the lifestyle they want to maintain into their twilight years, this is what happens. The company can no longer rely on the nicer side of human nature to carry their product through and eventually will have to yield......one way or another.
Good work Spirit pilots. This is a global issue and you won't be alone for very long.