In short, attention tends to drift away from vague problems that one is not sure how to handle, and toward more concrete problems at which one knows how to succeed. For example, employees' work habits are much easier to measure and to discipline than the quality of their work. As a result, managers often resort to measuring and managing work habits instead of work quality. Yet you cannot sell your employees' work habits to your customers, who are much more interested in the quality of your employee's work. Workplace interpersonals, vertically and laterally, are the most difficult to measure and manage.
Managers manage the mechanical aspects of the task.
Leaders tackle the less tangible but more critical aspects of team building. What's Noticed Gets Narrated. People organize their behavior by telling themselves and each other stories. Without changing the emotionally salient features of your workplace, the most that your communications and organization learning people can do is spin-doctor things for a short time. The Dilbert cartoon is a great example of how distrust and cynicism get folded into peoples' stories.