Do employees quit bad bosses?
As a matter of fact, they do.
And they do quit organizations that provide inadequate training and promotional opportunities, bonuses, and non-cash benefits, that foster (willingly or unwillingly) a negative climate, that assign insignificant tasks, or repetitive tasks, that do not leave enough autonomy, that do not give enough support.
The fact is, there is quite a lot that an organization and its leadership can do to prevent people from leaving. And considering the cost of voluntary turnover, the sooner they get to it, the better.