Managers don't like giving appraisals, and employees don't like getting them. Perhaps they're not liked because both parties suspect what the evidence has proved for decades: Traditional performance appraisals don't work.
People need to know what their jobs are.
Profit in business comes from repeat customers
When a worker has reached a stable state, further training will not help him.
A rational prediction has an explanation based on theory.
People are entitled to joy in work.