sorry for the snarky comment, but i'm pretty sure 10000% of HNers will agree that a Ph.D. is definitely an anti-prereq for doing a start-up; in fact, it's probably the worst use of your time if your goal is to found a start-up (UNLESS you want to develop your Ph.D. thesis into a start-up, which is hard, since what is popular in research and what makes $$$ are largely uncorrelated).
that's like spending 3 years earning a law degree and then complaining that it didn't help you with your goal of becoming an Olympic swimmer