After staying with any airline 10, 15, especially 20 years, leaving means cutting off your career. There is no retirement in the US if you leave after 15 years. Even 20. We can not restart our careers, which means having no bidding options and work for bank teller salaries again.
I would expect that most passengers are still too ignorant about our profession to know this fact, which everyone in the US airline industry is painfully aware of. Many do not even realize how blissfully ignorant they are.
Guess that's why some of us call passengers "self-loading" freight. But educated by rumours, Hollywood movies, and popular misconceptions, they know it all from "the inside".