Yes - but the point being presumably you wouldn't stay at that dead end unpaid position forever. As for the huge payoff in the end, that's sort of what entrepreneurship is as well - there's absolutely no certainty of a payoff but one does hope for it. Why would you take an unpaid internship though if there wasn't some expectation of "more"? If there is then yes, there's a value to that "option".

But presumably this isn't the case in some job like telemarketing or other really marginal menial tasks that you might realize within the first couple weeks if not month of doing it?