Ya know, after thousands of years [...] every culture on Earth settles on "Guess",

As far as my knowledge of cultures goes I'd guess that this is indeed the optimum for "settled" cultures where there are lots of rules and customes everybody knows from early on (precisely the conditions I gave in my earlier comment).

But that just means that it is applicable to 'normal' situations. Not under stress. Not for fast societal change. And maybe not for rationalists dealing with each other.