It isn't totally irrational, it's merely measuring the only metric we can measure objectively, in the usual way it's measured. The fact the measurement function is exactly backwards is not obvious; in fact, it's entirely reasonable to expect to pay more for taking up more of someone's time.

Locks are actually a very good (pathologically good?) example of this, because we usually have no idea how well and how often they succeeded and a single failure can be catastrophic. Therefore, it's very hard to tell how good of a job the locksmith who installed or fixed it did without being a locksmith yourself. Compare cars: With a car, you drive it around pretty often, and you get a feel for how it handles and smells and sounds relative to the baseline established when you first got it. There's a constant evaluation of factors relevant to how the car is actually doing. With a lock, if the lock is put in well and functioning properly, the successful evaluations are mostly unnoticed unless you have a camera watching the lock 24/7.