Does someone really believe that cognitive dissonance is a bad thing, as the article suggests at the end? I've just always imagined that feeling bad for poor decisions is how you learn not to do poor decisions.
Think about something you wanted and couldn't have. You probably tried to convince yourself you didn't want it anyway, and it was better for you that you didn't have it. It certainly keeps me more happy! But I also try to be conscious of it and use it like a tool more than a crutch.
I don't think cognitive dissonance is a bad thing. I don't see why should add a coping mechanism to acheive inner peace. If you instead saw that sometimes you win a grape, sometimes you loose one, you would have taught yourself a lesson, which should be bettar than denying facts about the world and yourself, if you are a man of science.
Yes! It is often distilled to this aphorism. But from my reading of it "sour grapes" is only one aspect. It is a more general concept that deals with how we resolve tensions between our beliefs and facts as we see them.