Not unless they're dogmatic about the language they're developing in, they aren't. I ran into people ALL THE EFFING TIME as a recruiter who refused to train in another language or environment because they were going to make less money if they moved on, even as the market for their current skillset dwindled to nothing.

That's a completely different issue from having injured your back or shoulder or knee so often that you need surgical corrections just so you can remain functional at a resting state.