http://www.pennylicious.com/2006/10/09/billionaire-dropouts/ A list of billionaires who did just fine despite being school and university drop-outs.
I think they got lucky. There are probably loads of students who dropped out of school to become something big, but never made it. Lets say Bill Gates didn't drop out of uni and start mircosoft, someone else would of, but course it wouldn't be called mircosoft.
I don't know if there is some empircal kind of evidence to verify this, but apparently people who go to work instead of taking the further education route are more likely to be qualified and have better know how in comparision to uni graduates.
