Apart from the volume characteristic this doesn't seem to hold. Vanguard creates ETFs on diversified baskets of stocks picked(rules based) by other people eg: S&P, Nasdaq etc. YC actually has to review each and every application and independently determine whether to accept them.

At a push, I'd go with - Investing in stocks:Vanguard :: Investing in companies : Random funds that will only invest if you have a brand-name lead investor

In a sense, and there's no shame in that. Index funds recognize that retail investors are bad at choosing where to place their money. I think it's equally plausible that venture investors are just as bad, and that spreading your bets within a certain range (in stocks, publicly traded companies) reduces risk and increases the likelihood of gain.