I really cannot fathom any investor that would not be absolutely ecstatic over a $3B exit for a product like this. Would any VCs care to comment on this specifically?
Therin lies the problem. That is the fundamental conflict between the diversified vc and the concentrated entrepreneur. It is not a secret, in fact a lot of good VCs want entrepreneurs to have a very clear understanding of what the end goal is.
I think you are perhaps conflating returns on the fund as a whole vis-a-vis returns on an investment by investment basis. The goal of a VC, as I understand it, is to only invest in companies that can provide 10x returns, providing that one of those investments does return 10x, one returns 2x, three break-even, and five are outright failures. If a VC owns 10% of a company that exits for $3B, then the VC gets $300M, which returns 75% of the total fund. I very seriously doubt any VC firm would have stopped this transaction.
Mendelson touches on this in a post: http://www.jasonmendelson.com/wp/archives/2013/06/the-vc-bar...