I was involved in some hiring decisions at Amazon many years ago. When I asked people, including my director, why we didn't do post mortems for when someone was

I was involved in some hiring decisions at Amazon many years ago. When I asked people, including my director, why we didn't do post mortems for when someone was fired for underperformance(and see where the interview process failed to pick up on that info, if it was available), all I got were strange looks.