I think you are wrong about reddit being "a really unique culture", at least in this context.
To me it seems very obvious that fundamentally it is exactly like how societies, communities, and communication has always operated, be it local gossip, newspapers, global communication, or hell even the differing thoughts/parts in our own minds.
Im not saying it hasnt changed things, of course the internet has changed most everything, just that the part we are talking about isnt something new. It has evolved certainly, but fundamentally the same.