Here is a secret – managers do not dislike employee performance reviews because the reviews are difficult, but because the managers are usually decent people.
Formal performance reviews are presented as a positive feedback mechanism that helps employees develop. The reality is that performance reviews usually happen once a year, and that is far too infrequent to be of any use. Even the most aggressive review programme maxes out at four times a year, still too infrequent to be of any use.
In a normally functioning company, useful feedback to any employee is in the form of continual informal feedback over the whole year. A formal review adds no real value to employee development over and above an informal feedback process.