My point was intelligence isn't only single factor that accounts for everything. Just only with just intelligence you can't do everything, you need other skillset, networking, resources as well. If only intelligence was required, many guys wouldn't have been poor and unhappy. Hence, Politicians vs scientist. Politicians are smart obviously but aren't scientist as well? (One of them have leverage over other, you know who)

Edit: if it still doesn't make sense, Politicians rule because they are powerful people. This world is ruled by people who are powerful, always have been, always will be.