Your entitlement is incredible.
Of course it isn't immoral to have private discussion groups. That's an absurd idea. Subreddits are private conversation spaces, not a public service, you aren't owed access to any of them. Do you have the same emotional reaction to invite only subreddits?
Have you stopped to consider for a moment why that filter might have been established?
I think moreso an opportunity for developers of specific genres to get attention in an increasingly crowded marketplace.