How then do you explain people like Donald Rumsfeld? He was highly intelligent by any standard measure, yet managed to make consistently bad decisions as Secretary of Defense.
William F. Buckley was very intelligent, but so was Gore Vidal.
There are many, many topics where increasing intelligence does not mean increasing convergence of conclusions. The further away you get from hard science, the easier it is to diverge... building (intelligently) upon incorrect and hard-to-falsify foundations.