Is a roof you have to redo every 20 years, or a paint that only lasts 10 years faulty? Is a car that needs brakes replaced every X thousand kilometers faulty?
It is only faulty if it does not run according to spec, or if you it run outside the spec.
Exactly. If the manual says "reboot every 51 hours", you do just that and all is fine. If you have to reboot every, say, 25 hours, something is broken.
It is only faulty if it does not run according to spec, or if you it run outside the spec.