

You don’t seem to understand, that they shouldn’t have to. Curate? Yes. Moderate? No.
Yes, semantics.
Users choose to Curate which communities they go into. They do this with full access to the rules of the community and the ability to instantly opt out of that community or instance should it become distasteful to them. Moderation of those communities is up to the owner of the community and is operated under the rules of the instance admins. Users choose to read and subscribe to these communities and if they’re not happy with the moderation then they can choose to curate those communities out of their feed.
What, exactly, is preventing instances who differ on the matter from co-existing?
Administrators who defederate over differences in moderation choices rather than moderate their own communities and let their users choose what communities they want to see.
Mandrake -> Whatever came on the Linux Magazine CD -> Backtrack -> Arch