I've watched people ride impossible (or at least very, very improbable) situations into the ground for any number of reasons. The most common is that they have their lives set up so there is no possible alternative. Sometimes that's no fault of their own, life happens and has spat them out and deposited them in that spot, and other times it is entirely self induced. I knew one dude, who was otherwise very together, who had a personal life that was a complete dumpster fire 24/7. For him, there was no alternative than to punch the clock every day, and live paycheck to paycheck. He wasn't going anywhere, because even a two week hiatus would cause financial catastrophe, even if there was more money on the back end. While he was fine professionally, I couldn't be around him more than a few minutes outside of work, because he was chaos incarnate, and it would spill into everything he touched outside of work.
No way on this green earth that I could tolerate that kind of personal situation, but I know several people who live right on the razor's edge, and happily exist there for years, even decades.
Other people just can't help to roll those dice one more time. "Hey, everyone quits, and when we survive, I'll be single digit seniority, left seat widebody".
To be fair, there is a healthy dose of luck involved. If you bail, you need to have a solid plan and hope that wherever you wind up is better than what you left. I knew a guy who had 10 uniforms in his closet, including Braniff, Eastern, and PanAm. Others do OK. Some people who bailed out of Braniff wound up at NWA, and retired whale captains. Some bailed out, went to Allegheny or Piedmont, then "local service carriers", and sat on the top of the list at USAir for a lot of years. A lot of senior guys who waited it out wound up throwing gear for their juniors.
It's definitely not black and white....lots of grey. How grey? Charcoal.