Eliminating what is not wanted or needed is profitable in itself.
The customer deserves to receive exactly what we have promised to produce - a clean room, a hot cup of coffee, a nonporous casing, a trip to the moon on goassamer wings.
When in doubt, delete it.
If you don't know what the defect level is, how do you know when to get mad?
We must define quality as conformance to specifications if we are to manage it.
It is always cheaper to do the job right the first time.