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.
The most basic problem is that performance appraisals often don't accurately assess performance.
Possibly the biggest issue, however, is that performance appraisals focus managers' attention on precisely the wrong thing: individual people. As W. Edwards Deming, the father of the quality movement, taught a long time ago, company performance often results more from variations in systems than from the individuals doing the work.