There is a great deal of diversity in thought on Reddit that is just banned outright by moderators. To pick a non-inflammatory example, a lot of dog subreddits

There is a great deal of diversity in thought on Reddit that is just banned outright by moderators. To pick a non-inflammatory example, a lot of dog subreddits will not allow any references to aversive training methods, which in their eyes include things like snapping your fingers or saying "no" in a sharp voice. What this means is you get a bunch of rival subreddits with different dogmatic beliefs, and people are banned for linking or even alluding to the existence of the others. There are examples of this kind of strict imposition of dogma by fiat in every reddit community, on matters large and small.