This, and the the fact that generally they were not taught at college/undergrad level, menat people who had learnt them were self-developers and/or early adopters etc. who had a "real" interest/passion and which then helped to differentiate them from the general masses.
Just because you know a functional language does not neccessarily make you any more/less smart. I know plenty of people who are brilliant at things like ML (they have maths backgrounds) but not so great at bigger picture thinking and putting it all together. the really smart ones are people who can do that.
Just imho how I see things.
Sorry if I was off topic in posts, maybe I was missing points as reposonding to many things at once.