> If you're turning down someone who wrote space shuttle firmware, because they "can't do fizzbuzz", then you are administering a terrible test and getting a false negative.
Or... large companies, particularly defense, excel at hiding mediocrity in their ranks, and it's easy for someone who produces no or negative work to be handed around rather than fired.
The reality here is that everyone is supposing their particular bias explains what happened.
No one seems to have asked what actually went wrong in the interview. Was the interviewee truly incompetent? Were they nervous? Were they fine at code but terrible at interviews? Was the language or environment unfamiliar? Had they just got off a plane after zero hours of sleep?
Without data, opinions are worthless. And generally, there's too little data about the relationship between interview performance and job performance, and too much unthinking mimicry: "We do this because everyone else does."
Or... large companies, particularly defense, excel at hiding mediocrity in their ranks, and it's easy for someone who produces no or negative work to be handed around rather than fired.