Indeed, and guess this works as a secondary filter. They don't want people who don't truly believe in the company to apply. At an early stage start-up you want people that are passionate/naive/delusional enough to want to work lots of unpaid overtime.
The value of the startup lottery ticket is based on how fast you can hire, how much hype you can build and how many users you can acquire. Most startups are a money pit, their only value is in acquiring their customer base.
Now that you mention it, what % of YC Startups even "succeed"? Would be fascinating to know. They're public about the companies that get accepted and you could have a few different criteria about what constitutes as success (getting funding? Existing 5 years later? etc)