"What this means is that YC is not looking for sustainable businesses, but homeruns. Which is entirely fair, that's the business they're in." Not really. He's

"What this means is that YC is not looking for sustainable businesses, but homeruns. Which is entirely fair, that's the business they're in." Not really. He's saying that going by the numbers _should_ be only looking for homeruns but, for a number of different reasons, they don't do that.