Pretty soon it'll be a public company, and there will be all sorts of institutional forces at work : If they mess up the entrepreneurial vision, no-one will be able to blame him (and make it stick).
This is precisely why a company that has already IPO'd, or one that has been sold outright or been raising private equity at a lower valuation, is a better example (in my very humble opinion).
You've precisely underlined the precarious situation Facebook is in. Enormous pressure on Mr. Zuckerberg to make a good IPO, because afterward he is off the hook.
