YC pretty openly and deliberately tries to convince prospective and actual Big Tech employees who are curious or on the fence to quit and do a startup already. There's a great Startup School video about this [0]. I think the critics are right about "doing a startup" and chasing an exit having become an equally normal, precedented, socially-supported path as joining a big company and chasing promotions. But I'd be surprised if YC itself would characterize that as failure.
HN is a lot more jaded towards startups and founders’ games these days. Back in late 2019 there was this thread about a pre-YC Garry Tan video where the tone of the discussion was fiercely against working for startups, saying it was better to join FAANG or start your own company instead:
[0] https://www.youtube.com/watch?v=sM2reZib2RY