I agree with these things to describe why turnaround would be due to bad things.
Think of this though. Maybe its a great situation causing the turnaround. Maybe its a great leader inspiring others to want to be a head director, or give them the skills to land a job in a successful situation. I would love to keep great assistants for a long time! Truth is, I would love even more for them to want to move up in our career. If that means they learn some things in a year or two and realize that the can do this and move on, then I am a successful leader. The grass isn't always greener, but I feel most are quick to assume its a bad situation. Could most definitely be that way, but you never know how tight the shoes may or may not be unless you wear them.