> does the camera or grip or other such professional, need to be plot-level motivated to do their job with skill, grace, pride, and.. with paycheque in hand?
I've never been involved in films, but from my own experience, the answer is a strong 'yes' - people want to have faith that the effort they're putting in will lead to something good. It's part of the process that sometimes projects fail, but generally people need to have hope, in order to feel that their work has meaning.
An interesting recent example is the debacle around the development of the game Concord, which is said to have been plagued by toxic positivity[0]. Reading up about this, I understand that people who worked on that came out with a very negative experience, exacerbated by the disastrous launch.