They really ought to be, what's the rational value in putting the time and effort into chess to become a world champion at it.

I played it semi-seriously when I was young, but gave it up when in order to get to the next level I'd have to study more than play. Most of the people I know who were good at a competitive intellectual game dropped out of school to pursue it, because they couldn't handle studying at that level for both.

I find it rather difficult to believe that pursuing chess over school is the rationally optimal choice, so I wouldn't be remotely surprised to find that those who get to that level are irrational or superstitious when it comes to non-chess problems.