It could mean that, but in all likelihood it means that some YC funded companies make huge amounts of money for YC that sufficiently balances the losses that they keep doing it.
Ya know, like most investment (that works).
Joe Bob’s Burgers don’t have the luxury of losing money hoping they can survive long enough to find the “greater fool” either via acquisition or IPO.
It doesn't matter. The only question for YC is whether they make money or not. They make money on some of their investments, and lose it on others. It's fairly clear that on average, that is, summed across all winners and losers, they make money overall.
On the other hand, Andy's Average Appetizers is of no particular interest to VC money, or any other money really, and so yep, they're going to go under because they don't anything that attracts enough money to make them viable (possibly at a higher living wage standard, possibly at current minimum wage standards).