Earlier quoted context omitted.
Performance reviews aren't bullshit - it's crucial to have an objective (as objective as possible) system for measuring performance both to reward your high performers and to understand your low performers whether to provide support or to document reasons for firing them. Several kinds of performance management system such as mandatory percentages for each rating level ARE bullshit, but without performance management…
You failed the moment you said objective. Any such system needs to acknowledge right off the bat that these assessments are subjective, subject to human error and re-enforcing bias etc. Otherwise you're just high on your own supply.
Also, a well built subjective review process is better than no process, for instance, using peers and customer opinions as input.