Just to begin with, the above is a terrible way to structure an inductive argument about something as variable has human behavior. Obviously few people are "completely incapable of good decisions or are the Chosen Of God" and no important decisions in life are "meaningless". It is, however, the case that most decisions don't matter all that much and that, when they do, people usual do a pretty good job without special training.
But the real issue that you're missing is opportunity cost. Lots of people don't know how to read or do arithmetic. Lots of people can't manage personal finances. Lots of people need more training to get a better job. Lots of people suffer from addiction. Lots of people don't have significant chunks of free time. Lots of people have children to raise. Almost everyone could benefit from learning something but many people either do not have the time or would benefit far more from learning a particular skill or trade rather than Bayesian math and how to identify cognitive biases.
Almost everyone could benefit from learning something but many people either do not have the time or would benefit far more from learning a particular skill or trade rather than Bayesian math and how to identify cognitive biases.
I'm not disagreeing with this at all. But given the option of teaching someone nothing or teaching them this? I think it's a net gain for them to learn how to change their mind. And I think most people have room in their life to pretty easily be casually taught a simple skill like this, or at least the basics. I've been teaching it as part of casual conversations with my roommate just because I enjoy talking about it.
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.