For my two cents we're all very naïve in regards to the presidency, especially from a historical context. NO ONE comes into the office knowing how to be president. The challenges that present themselves are far greater than all the speech making and critique by armchair pundits.
Secondly the presidency cannot be run like a corporation. So in my view all the corporate executive experience in the world won't matter worth a damn when that person is sitting in the Oval Office. Additionally, as asxshadow indicates there are limits as to what a president can do. The best way to look at it is the president is the visible representation of a huge bureaucracy that encompasses millions of people and agencies most Americans never heard of. I don't know of a corporation that's comparable.
So we have to be careful with the infatuation of so called experience. By some of the criteria used today Abraham Lincoln might not have been elected.