Not necessarily. There are some who go into non-profits or governments, and others who take even more nonconventional paths (additional degrees). They aren't losers. That's hard to pull off given MBA debt, though.

The ones who end up at typical startup management jobs are the bottom of the class, though. They weren't good enough for stat-arb hedge funds or billion-dollar deals, so they got stuck managing nerds.

If someone 10 years out of an MBA program with some success to his name said that he wanted to run a tech startup, I'd be inclined to support him. On the other hand, if he was a fresh Stanford grad and couldn't do better than a VP-level position at a Series A or B startup, I'd be inclined to think he was a third-stringer.