Just another personal observation on top executives at large companies...
In my day to day business dealings I get to meet lots of business owners and managers, and an unusual number of startup business owners (one of the first things they need is graphics when they start a new business). Every once in a while I will meet a former executive of a large company who is absolutely convinced that his "business experiance" will make him highly successful in is entrapanurial endevor.
About 10 years ago a former Pepsi executive started a company competing with mine. He hired one of my former employees who I was still on good terms with, and she told me that he said that he would put my business out of business because he had so much experiance and had brand new equipment and had purchased rights to a very succesful franchies. Less that two years later, I got my employee back, she bailed on the company before they went bankrupt. The guy lost $2 million bucks, including botgh his houses, his cars, and all of his life savings. He had become a buddy of a guy who was a print broker, and the print broker convinced him to just sell printing instead of having to produce it. I was one of the main producers for the print broker, and eventually the former Pepsi exec had to start purchasing from me as most of the other local printers didn't want to have anything to do with him (mostly because he badmouthed them). I ended up purchasing all of his inventory and equipment at the bankruptcy auction. In the end, just before he gave up on brokering and went running back to his old job with Pepsi with his tail tucked between his legs, I had his employees and equipment and customers, I even considered purchasing his foreclosed house, but I didn't because it wouldn't make a good rental property.
The guy had been a high ranking executive at Pepsi, but in reality he had NO business experiance. At Pepsi he had never processed a payroll, the people who reported to him were highly paid professionals and supervising them is NOTHING like supervising lower paid less skilled employees, he had never developed a marketing plan, he had only negotiated equipment purchases for his specific area of responsibility and had never negotiated for raw materials, he had never had to deal with cash flow issues, if he had a potential legal issue that issue was simply sent over to the legal department, he had never purchased commercial property, he had never supervised the construction of a new facility, he had never had to deal with customers on a face to face basis. Basically, he was sheltered from the real business world by Pepsi.
As far as creating a business from scratch, the people that I have found to be most successful tend to be people who are young, people who had to work their way through college, and had little or no corporate experiance and learned as they worked through the issues by themselves. Generally, the people who make the best entrapanures are the ones who are too dumb and inexperianced to realize that they "cant" do what they are aiming to do. If you have never been taught that you cant do something, then you are more likely to do it and make it work.
I would think that people who started their own companies, even if they failed or succeeded with modist success, would make a much better CEO of a major corporation than people who were hired directly into middle managment with a MBA from a prestigeous school but no real life experiance business experiance outside of their corporate job. There are tens or maybe even hundreds of thousands of people who have likely had more challenging real life business experiance that most top CEO's.