I don't know about other people, but there's a number past which I do not care. N > 10^7 in my pocket after tax, I'm out, regardless of circumstances, regardless of ability to earn more. No ragrets.
That said, a social network centered on photo sharing and a slightly more handy version of email or event sharing is definitely not one of these high impact ventures in my opinion, so yes, I would have sold that long ago and went to work on something more meaningful.