As long as holding myself responsible for bad calls doesn't become a ritual where I discharge my obligation by identifying (by hindsight) the first clue that, if more highly weighted, would have led me to victory, I agree: my failures should be examined in case there is anything I can rightly learn from them. When the reasons for an outcome are murky even in hindsight (e.g. investment losses), the risk of wrong learning is heightened.

As applied to willpower (rather than judgment), the argument works - you had better be able to understand and control your own mental state, or else no one will. But I sometimes feel that I need more than self-blame to win over my own laziness.