The smartest all jumped on career ladders because of the head start from their degrees and grades. The non-technical went to banks because what other profession pays $100k a year for a liberal arts degree? The technical went to the most recognizable companies that would take them and pay them a lot of money.
The entrepreneurs are a much more interesting bunch; most are technical, some never had a corporate job, some did YC, some left their corporate job and are mindlessly trying to be entrepreneurs, lots have raised funding, and a very select few have exited or hit Series C.