I know that my education, and work experience will payout huge when I start a company. The emotional and intellectual development learned in school and working for companies afterwards will be an amazing asset and would be for anyone.
When you drop out, you have nothing to lose, and so you are "all in", which allows you to take bigger risks.
Using the poker example, when you have nothing to loose you are effectively playing "on tilt". When I was broke (limited commissions coming in), and I didn't know what to do I started a wedding photography business. I made a profit, but I wasn't making real money and there was no real big opportunity. The next thing I work on will be massive in ambition since the opportunity cost would be leaving my insanely awesome job.
Having nothing makes most people focus on survival, having some income and confidence that there is another job out there if it doesn't work has to help people more than it hurts them.
And, as you read this, you are probably thinking about your friends working at big companies that would never leave to start a company. I would argue that the vast majority of people are not entrepreneurs and not going to school wouldn't change that. They would just have a worse job.
Generally, I think education allows you to lower the risk of achieving a given return. Or, it could be seen as allowing a higher return for a given amount of risk.
Maybe that's the definition of a start-up: a company that sets a level of risk, then tries to maximise the returns on that risk? A "normal" company does it the other way: sets a level of return then minimises the risk required to achieve the return.