Management structures are often designed to avoid failure. An unintended consequence is undermining top performers.

Marcus Buckingham describes this in First, Break All the Rules based on Gallup Research across a range of professions.

…in numerous job functions the best and the worst performers shared some, but not all, traits. Both the best and the worst salespeople have call reluctance; the mediocre performers did not. Both the best and the worst nurses had a personal connection with their patients; mediocre nurses stayed aloof. What was important is what the top performers did about this strong emotional link; they used it to empower and motivate them. The poor performers used it to shrink from effective action. Those with no emotional attachment lacked the motivation to excel.

Hospitals rotate shifts so that nurses cannot form personal attachments to patients. Prevents poor performing nurses from burning out. Doesn’t impact mediocre nurses who don’t engage anyway. Prevents the best nurses from giving the kind of care that improves patient outcomes.

Compulsory testing and centralized lesson plans are designed to ensure poor teachers raise poor student performance but makes it much harder for great teachers to innovate and personalize instruction and bores precocious students ready to go beyond core instruction.

If the core difference between poor and excellent performers is that the best are motivated and empowered by their emotional engagement to their work, then it follows if you demotivate and disempower your best performers you remove the distinction.

Under a poor leader, the exceptional will under-perform the mediocre.