If that were true, there'd be no point in ever applying a second time to YC. Anecdotally, people do get accepted after 2-4 failures. Maybe YC was on the fence

If that were true, there'd be no point in ever applying a second time to YC. Anecdotally, people do get accepted after 2-4 failures. Maybe YC was on the fence about those founders and their willingness to slam themselves against a wall repeatedly tipped the scales, or maybe they invest in a certain kind of founder and when they run out of those they invest in "promising" ideas.