Comment by nottorp

Your last paragraph just said that if you hire people and tell them their earnings depend on $METRIC they will optimize said metric.

The argument here is which metric, or are metrics good for anything? [1]

[1] Except ditch digging and children. It is well known that 9 people will dig a ditch in 1/9 the time one person will, and 9 women will make a baby in 1 month instead of 9.