I agree - whenever interview processes come up, commenters mostly criticise the interview processes for excluding good candidates.
But that's only one part of the equation - the number of unsuitable candidates that slip through is normally more important.
Suppose that somehow we magically know that 20% of candidates would be good hires - and the other 80% are unsuitable. But we don't know which are which!
As an interviewer, I'd be very happy with an interview process that discards 50% of the good candidates and 99% of the unsuitable candidates, because that leaves me with 10 good hires and 1 unsuitable hire for every 100 candidates.
On the other hand, if a different interview process discarded 20% of the good candidates and 80% of the unsuitable candidates, that would result in 16 good hires and 16 unsuitable hires - which would be disastrous!
Even from the point of the interviewee, one probably wouldn't want to work somewhere where 50% of your colleagues are not suited to their jobs!
Summary - it's a shame to discard good candidates, but it's worse to let too many unsuitable candidates slip through ...
But that's only one part of the equation - the number of unsuitable candidates that slip through is normally more important.
Suppose that somehow we magically know that 20% of candidates would be good hires - and the other 80% are unsuitable. But we don't know which are which!
As an interviewer, I'd be very happy with an interview process that discards 50% of the good candidates and 99% of the unsuitable candidates, because that leaves me with 10 good hires and 1 unsuitable hire for every 100 candidates.
On the other hand, if a different interview process discarded 20% of the good candidates and 80% of the unsuitable candidates, that would result in 16 good hires and 16 unsuitable hires - which would be disastrous!
Even from the point of the interviewee, one probably wouldn't want to work somewhere where 50% of your colleagues are not suited to their jobs!
Summary - it's a shame to discard good candidates, but it's worse to let too many unsuitable candidates slip through ...