Just like employees, bosses can be either good or bad. If the boss is not doing something that they are supposed to be doing, then they need to know about it. It is important that the employees have a good understanding with their boss, but it is also important for the boss to do what is expected of them. In my opinion, it would be a good idea for employees to give performance reviews to their bosses.
How many of us have had a job where we worked for an incompetent boss but felt helpless to do anything about it? I'd be willing to bet many of us have. If employees were able to submit anonymous performance reviews of their bosses to the company's corporate department, it would help make employees feel their opinion matters to the company.
Making sure the job is done isn't all a boss is responsible for. He or she is responsible for ensuring that the work environment, be it job, pay or his management style is tuned to maximize worker productivity. Worker satisfaction with the boss will have an impact on this. It only makes sense that the employee should have a say in determining the boss's performance.
The basic result of a performance review is for one to know how well they're performing at their jobs. If a bad employee is never told that he is bad, he will continue to be bad. Reviews offer insight into performance. If bosses had annual reviews, they would be inclined to work harder because then they might feel their jobs were at risk.