When you hang out in places like HN it seems like everyone has this insane drive to succeed and be the best and conquer the world. The truth is that lots of (most?) people are happy getting their paycheck and going home every day. They don't want more responsibility, they don't want to climb the corporate ladder, they don't want to disrupt any industries, they just want to watch their kid play softball.
Sure, they love to say "oh I could run this company better!" but they wouldn't actually want to do it. If you read Yishan's AMA about a day in the life of a CEO it's very similar - most people DON'T want that job and everything that it entails (being on call 24/7 and being 100% responsible for every aspect of the business).