It's a moderation problem, and if you don't have the right "vibes" you don't get in.
It's arbitrary? Yes. Prone to false positives? Yes. Does it work? Also yes.
That's how clubs maintain their unique identity.
I used to resent the door policies but after this experience (it really destroyed the atmosphere!), I am glad they exist.
Oh god, the horror. How did you cope? Did you still manage to express yourself with these soul sucking chino wearers nearby? It's a good thing that indiviualism is so non-judgemental huh.
And paying to get into places where you couldn't get otherwise (by "vibes" only) is enough to tell you're out of place.
Elon Musk tried to enter Berghain and was refused; Kanye West tried to jump the line at Mustafa and was sent back.