Facebook decided to have all that growth in value for insiders only. And it's not like they wanted to be a private company, so the outcome is planned.
By not leaving any money on the table, and having joe public not share and invest in their success, when the government starts to beat down on them, there won't be much public support for FB.
And pg is right: nor will there be much support for those following in their footsteps. Scorched Earth. Those investors did well (and many HN peeps on SecondMarket). So well in fact, it won't happen again. Not for a long while.