I can't speak for the others, but Zuckerberg went to Ardsley High in Westchester County before going to Exeter. He also took at least one computer course at Mer

I can't speak for the others, but Zuckerberg went to Ardsley High in Westchester County before going to Exeter. He also took at least one computer course at Mercy College while still in high school. Also, going to a wealthy private high school does not mean one is from wealth. Top private schools, much like the Ivies, offer need-blind and need-based admission. It's likely a many of your listed founders were also scholarship students. If you want a better indicator of what makes a successful founder, observe past alumni of summer programs like the Duke Center for Talented Youth.