I think it's partly because Fediverse users have often actively and explicitly sought to reject folks of those different mindsets.
SO OFTEN I've seen talk about how this is supposed to be a safe space to get away from people with alternative perspectives.
And yes, there is also some blocking going on. Folks are proud of who they block to maintain their echo chamber here.
Without the pushback from different perspectives, the conspiracy theories and rambling are feel to thrive.
@volkris @RachelThornSub
Yeah - I checked and her server blocks over 150 sites including most of the "right-wing" ones she might be looking for.
She won't get this message for that reason.