Hard-working employees want colleagues with the same qualities. If their manager hires or promotes undeserving people, the best people will soon start leaving.
Talented people are usually enthusiastic, and managers should help them keep up their enthusiasm by offering interesting job opportunities. Strictly focusing on a narrow range of tasks and procedures can be detrimental.
The best workers have a natural interest in constantly changing and improving things. If their manager doesn't allow them to do so, it will limit not only them, but also himself.
A good manager puts challenges in front of his people to achieve things that seem unachievable at first. He doesn't let them only work on boring and simple tasks.