A book club meets once a week at the public library to talk about classic literature. A few of the members want to also have a chat about Disneyworld, or tell off-color jokes, but some of the group doesn't want to talk about or listen about that. There is no way to resolve this situation that doesn't involve someone forcing their preference onto someone else. The pro people could keep talking about it, forcing their preference onto the anti people. The anti people could suppress the conversation, forcing their preference onto the pro people. Or the anti people could leave entirely, avoiding both what they don't want to listen to and what they do. None of these solutions is good.
An email listserv is formed to talk about classic literature, but a few of the members want to chat about Disneyworld, or tell off-color jokes, and again some on the list don't want to talk or listen to that. There are two easy ways to fix this that do not involve anyone forcing their preferences onto anyone else, that allow everyone involved to see exactly the discussion they want. One is creating a second listserv for those "off topic" posts (assuming that listservs are free and plentiful to set up). The other and perhaps better is to have those off-topic posts tagged with something like "[OT]", and then those who don't want to hear them can effortlessly filter them out.
That we can do this takes away the only argument anyone could have made to suppress or censor those off-topic discussions. Therefore, filtering is actually a way to avoid censorship.
So why do daft people who haven't quite "gotten" the ways email differs from sitting in a room insist on taking a request for tagging to be censorship when it's exactly not censorship? Censorship isn't me choosing not to listen to you; it's not even me saying "you should talk about that somewhere else, not here" (in a privately run, topic-focused forum). Censorship is preventing you from saying something. Period.