You're going to crucify an emerging technology for being where edge groups congregate, even though that's that's been the MO of the Internet since BBS days?!
Some technologies (e.g. Secure Scuttlebutt) have the ability for subgroups to exist without aggressively recommending content to every user, as an inherent property of their design; I think "should Peertube adopt some aspects of these designs" is a valid question.
On the other hand, if PeerTube is used to host a lot of pro-facist video content made by racists that could be a problem for PeerTube. It's an existential threat to the technology. If governments and ISPs see it as predominantly used for that then they'll ban it. If more legitimate users see it being used for that then they'll stop peering video content and it'll become much less useful. PeerTube will live or die by the network effect it needs to be effective. Guarding against the "wrong" users, or at least marketing it so that more of the "right" users join, is essential. Nothing about that is a judgement on the content or the users; it's the simple reality of developing technology in a society full of different opinions.