Praise is good for a while, warm and provides encouragement, but if it continue too long, it can blind, fatten and cripple the recipient. An overly high opinion of oneself resulting from too much praise from a manager spreads like wildfire within the organization, unfortunately. There will be a whole row of kings who actually wear no crown. At some point, there will be no more results to praise.
Key Principle of a Leader #45: Excessive praise is risky and counterproductive