Oh dear.
IF we followed that policy nothing would ever fly again
If we followed that policy then many of the accidents were discuss would never have occurred. But I accept you are in exalted company in believing we should not have a process that aims to eliminate design defects. (If you had said
FAULTS I'd tend to agree with you, but they are two entirely different things). It would be interesting seeing the MAA 's reaction to a formal proposal along those lines. Only an idiot would put their name to it.
On the vast majority of examples cited here, the aircraft would have been compliant, safe and available for service use far earlier had mandated policies been implemented up front, instead of taking short cuts and then having to regress. Case in point - Rivet Joint.