I strongly suspect that fewer idiots would lead to fewer problems (but someone who knows that they are an idiot, and listens closely to the advice of more intelligent people, may cause fewer problems than an arrogant but more intelligent person who believes that no-one can give him good advice). However, I don't think that fewer geniuses would dramatically reduce problems (on the basis that a problem caused by a genius is often temporary - like the financial crisis - while a problem solved by a genius - like the invention of X for a given X - is often solved permanently).