If it is not worthwhile for competent adults to learn something as basic as "how to change their mind" then I would have to agree with the conclusion that we are doomed.
If something's being worthwhile or not is a major consideration in whether or not we are doomed, doesn't that make it worthwhile? OTOH, if you mean "If we are the same amount of doomed whether or not people learn to change their minds, then we are very doomed," you are right.
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.