Why People Really Quit Their Jobs
hbr.org
hbr.org
In my case I've given it a lot of thought, and even engaged in new projects which have been more interesting and successful, but it's still quite clear that I have to leave.
But for the vast majority of folks they get less than satisfactory salary, uncertainty about the prospect of the company. In a situation like that may be the dynamics and incentives would vary widely ( work satisfaction could just be a little piece of the puzzle)