Just ban everything and everyone you don’t agree with.
They were specific about what they didn't agree with: Authoritarianism.
And if they don't want to tolerate guests from an instance that allows Zionism, then good. Any feddit.org members who think their admins' permissiveness is tolerable are complicit in the promotion of Zionism, even if they aren't intentionally complicit. Yes, hanging around with pro-genocide people should earn punishment, such as ostracization until they stop hanging around pro-genocide people. It's a social media account on the Fediverse, switching isn't difficult.
We did the same thing to Wolfballs, until their admin closed the instance because it was filled with literal neo-Nazis calling the admin a 'race-traitor'. Tolerating every belief is utopian, pointless and self-destructive.



wut? Even lemmygrad.ml doesn't - their support of the Russian Federation's invasion has always been critical, not full. Just like their support for Hamas is critical - it's extremely obvious that neither the capitalist-run RF nor the Islamist Hamas are groups they agree with at all.
(I am not a campist, I'm simply explaining the campist concept of "critical support")