That's a dishonest thing to say. The truth is that you can't possibly know which companies, if you had funded them, would have become great companies.
If Larry and Sergey had done their post-graduate work in Moldova, the world wouldn't have Google. (Remember they shopped Page Rank to places like Yahoo, who didn't want it. As an idea, no one believed in it.) The connections at Stanford gave them access to capital which they otherwise would not have had, which allowed them to prove the concept. Without that funding, Page Rank would be just another dissertation.