Just imagine that the job becomes like a surrogate to the persons' actual identity. They identify with their own job and think it makes their lives meaningful even though they might intensely dislike it. For instance, the people I've met who work in medicine who were very much like that - one of my best friends went through med school. Where I live doctors often work long hours besides having extremely stressful jobs (and so take self-comforting addictions like smoking, caffeine abuse and drinking). It seems as if they're often led into the profession by rather unlofty motives like pay or prestige, but I also know that many give some inherent value to their work because they're helping people. Would they'd be better off in another job? I know it's not up to me to tell, I feel as if many would. Specially the ones very much sensitive about patient loss. Because it's a hard thing to deal with anyway, but it hits them the most.

So yeah, I think that someone might stay in a profession he might not actually personally like for some arbitrarily long periods of time. At least in principle. Don't know how it might apply to other professions though, because I don't see why people would keep programming for ethical reasons - unless they're deathly afraid of the coming machine revolution.