The quality of the outcome casts a shadow over our ability to see the quality of the decision.
We want outcome quality to align with decision quality. We want the world to make sense in this way, to be less random than it is. In trying to get this alignment, we lose sight of the fact that for most decisions, there are lots of ways things could turn out.
Experience is supposed to by our best teacher, but sometimes we draw a connection between outcome quality and decision quality that is too tight. Doing so distorts our ability to use those experiences to figure out which decisions were good and which were bad.