It's all well and good until you get judged by a bunch of completely borked-up, unfair metrics. The computer sets you to running halfway across a gigantic warehouse again and again, then measures your "picks per hour" vs somebody who consistently ends up in a tiny corner of the warehouse. Your manager agrees that it's not a problem and tells you not to worry, then a few months down the line some algorithm decides to give your lucky coworker a big raise and you don't get a boost at all.

Thankfully I haven't had to deal with any metrics like this for more than a couple of months at a time.. Since engineers' specialty is to optimize ratings, it's an obvious-enough waste of time to apply them that they're usually short-lived.