We were very lucky to have Julian, and we would have been even better off with YC, which is a superset. In addition to all the above, you get other startups as colleagues, and startup-specific advice.
I am not saying YC is bad - far from it - I am myself a big fan.
The only thing I was pointing out was that the YC interview rejection/acceptance should ideally have only as much importance as being rejected/accepted from probably another angel investor - which happens more often than not in the startup world and consequently should not be given a lot of importance.
The entrepreneurs who are in the trenches shouldnt really care as much about a rejection or two - its no big deal and even an acceptance might not be a big deal - but if you build something that people want and have something to show for it then feel free to jump over the moon.
Success in the flights industry can be lucrative but if you don't hit a home run you get zip. Solution: impress some knowledgeable, connected people who will be determined to help you if they like you. These guys passed, maybe they have reason to be happy.
Where did I say that? My point was that we were lucky to get a subset of YC.