I think most people would admit that Vladimir Putin seems like a likeable person - or at least say they respect him. How many like George Walker Bush as a person - or even respect him? What kind of leader would you prefer for your country? Being smart is certainly not a disadvantage. Personally I like Ron Paul a lot...
The systemic effect of having a "stupid leader" is a transfer of real power of influence to his counsel. This is an undeniable fact. It was very much proven with GWB, and it will be a continuation with McCain...