I only see unwarranted 'clubbiness' in the negative spaces- that is, in the supplicant/resented attitude of a minority of the people that didn't make the filter. I'm sure most of you understand that there is no room for all, and that the YCombinator folks are not taking anything from you by making others happy.
It's not like pg is rubbing it in your face either. He even went out of his way to write an it's-not-you-it's-me essay, to prevent applicants from taking the rejection personally.