A lot of such issues could likely be resolved by a better thought out protocol. There are certainly plenty of self righteous people who would refuse to federate purely on principle but more typically the issue is simply that one does not wish to be exposed to or traffic in any way the content in question. A well thought out self categorization system could largely address that need - you'd only need to refuse to peer with those who failed to apply it. AI also makes any such effort easier than ever.