You can also find very serious and explicit product and cultural decisions in all of Facebook competitors, and indeed in all startups. Everyone thinks they have the next billion dollar company, but the majority do not.
All you are doing is looking in hindsight and using Facebook's profits as justification for Zuckerberg's decisions or to credit him with something other than luck.
You are defining intelligence, intuition, or brilliance based on success. No wonder your observations support your view, it's impossible not to.
As for staying in school, there are two very good reasons for it. 1) Learning is the only way to actually not be ignorant and university is still one of the best environments to learn. 2) Every smart investor hedges their bets. Every investor recognizes risk and that startups are risky and that most don't succeed. Founders are not some sort of exception. Thus, finishing school is hedging your bets. It's good advice.
I'm sure you deeply want to believe that luck has little to do with it. It's a nice feel good story. But you don't have a convincing argument. Everyone recognizes that various types of skills are important, but nobody has ever put forth a magic formula that will guarantee a successful business. Until that happens, we cannot claim that luck has nothing to do with it.