And I think he's useful at least as a voice that challenges some conventional mental models for looking at things in math, finance, and decision making.
He's not an infallible visionary and should not be taken as gospel, but I don't think we should disqualify all of his ideas and opinions. I've enjoyed reading a lot of his books.
However, as you said, he's not a good introduction into the economy and probably isn't accessible for many beginners.
But now I'm searching the comments wondering why the titles don't match.
To someone who doesn't do martial arts, white belt means something to me (inexperienced), as does black belt, all other colours are unknown points in between.
In conclusion. The HN crowd are pedantic and argumentative, so stay away from metaphors. :)