I think one way to avoid having to call this regret of rationality would be to see optimism as deceiving, not yourself, but your immune system. The fact that the human body acts differently depending on the person's beliefs is a problem with human biology, which should be fixed. If Omega does the same thing to an AI, Omega is harming that AI, and the AI should try to make Omega stop it.
Well, deceiving somehting else by means of deceiving yourself still involves doublethink. It's the same as saying humans should not try to be rational.
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
If continuing the discussion becomes impractical, that means you win at open threads; a celebratory top-level post on the topic is traditional.