I mean, I get "ignoring" someone so they don't show up when you log into whatever instance you're in, whether it's the AT Protocol or ActivityPub, but like... if someone somehow decides to do work on top of one of these protocols and extend it to allow people to basically comment on things that a victim user doesn't want to allow an antagonist to take part in, I mean, aren't you just like effectively putting fingers in your ears while someone in another room talks about you?
I don't see how, without centralization, you can say to the world, "Hey, here's my content, interact with it," and then also say, "Oh you, over there, you can't participate in this thing that I am doing."
Like, depending on the shape of the graph, that doesn't make any sense. You effectively cannot do that without just creating a bunch of silos that are non-cooperative.
Bam, you've reinvented centralization with extra steps.