The technique is basically an after action debriefing. In settings where people die from mistakes such as military operations and space flight, a political process which seeks to assign blame to individuals is often of little utility.

The actions of the deceased often contribute to their death. The only lesson from assigning blame to the pilot for pilot-error is "Try not to make mistakes". Placing the system at the center of the investigation makes for better checklists that reduce the probability of pilot error for many pilots.

"Don't wear red and march in a straight line" is a better tactic than "Don't get shot."