Folks who truly never compromise or give up are great, except when they pick the wrong horse.
YC is like a doctor which takes a 10% cut of the lifetime earnings of every baby they deliver. Adding some value, yes, and some kids won't earn very much, but the wealth earned by the new human would have almost certainly been earned regardless of the doctor's skill. And this doctor happens to deliver half the babies of the entire state of California.
The cult part was thanks to PaulG. As long as that continues, YC will be successful.
OpenAI was the result of a fear that big tech. was going to monopolize all the fruits from recent deep learning advances, because they had all the data and the money. That was the obvious new hotness to get into. Proprietary AI was an existential risk to VC livelihoods.