> The metrics make reporting to higher ups easier, no doubt.

It's not about being "easy". It's about being objective, verifiable, and demonstratably unbiased. It's about justifying how you rank the performance in a way that's impossible to refute.

> But the situation you describe is a classic sign of a shit manager:

It's not, and frankly this "shit manager" accusation is an infantile remark that screams a failure to understand what it means to perform well.