I think its hard to prove without a very large statistical data set as we see that 8 out 10 times might IPO but in the next 50 years (if that would be possible) it might be 0 out of the next 10.

IMO the reason is that things change. People change. Markets change. The world just doesn't stay static. But our tendency is indeed to trust people who did something and I would probably also trust a person more given certain specifics as above.