>I wish that were true. In practice, server admins are more than happy to block federation with entire other domains (and all associated users, hundreds or thousands at a time) based on little more than gossip and rumor.
That's the prerogative of the instance owner. If the instance owner doesn't want to see certain posts, or undesirable posts from certain users, they don't have to. It's their own server, and they can choose what content to host on there.
If you don't like that fact, you can go to an instance which has few or little in the way of defederation (and there are many), or you can host your own instance. But what's unreasonable is to demand that server owners should have to allow certain communication on their platforms. If the owner demands you must wear a chicken hat when you post, you'd better wear the chicken hat. Or just go elsewhere, if you don't like that rule.
Would you demand the same thing of HN? Should there be no moderation at all? What about Twitter? If I were the owner of an instance, and I found out I'm seeing child porn on my server's timeline, would it be unreasonable of me to unsubscribe from that user, or defederate with their instance, if their instance has a habit of allowing that material? Let's say it's not illegal, but morally undesirable to the owner of the instance. Why should that change anything?
You have freedom of speech, but you (and the instance owners) have freedom of association. To take away one necessarily lessens the other. By joining to an instance, you agree to the administration policy, and that includes defederation policies. Just as you shouldn't be annoyed at being banned for spamming (e.g. on the basis of an anti-spam rule), you shouldn't be annoyed at the instance owner defederating (e.g. on the basis of a "no child porn" rule).
You seem to be confusing my complaining about a behavior (instance operators being stupid) and my being entitled to force them to behave in a non-stupid way. This is a common misunderstanding.
You're preaching to the choir about "their server, their rules". I just think that censorship is dumb, and server admins that do this are dumb. They're entirely within their rights to be dumb on their own hardware.
I do run my own instance. And thousands of people, some of whom I wish to read, have been denied the possibility of me following them (despite their toots still available on the public internet for anyone, myself included, to view) because one such admin has been this type of dumb.
That's the prerogative of the instance owner. If the instance owner doesn't want to see certain posts, or undesirable posts from certain users, they don't have to. It's their own server, and they can choose what content to host on there.
If you don't like that fact, you can go to an instance which has few or little in the way of defederation (and there are many), or you can host your own instance. But what's unreasonable is to demand that server owners should have to allow certain communication on their platforms. If the owner demands you must wear a chicken hat when you post, you'd better wear the chicken hat. Or just go elsewhere, if you don't like that rule.
Would you demand the same thing of HN? Should there be no moderation at all? What about Twitter? If I were the owner of an instance, and I found out I'm seeing child porn on my server's timeline, would it be unreasonable of me to unsubscribe from that user, or defederate with their instance, if their instance has a habit of allowing that material? Let's say it's not illegal, but morally undesirable to the owner of the instance. Why should that change anything?
You have freedom of speech, but you (and the instance owners) have freedom of association. To take away one necessarily lessens the other. By joining to an instance, you agree to the administration policy, and that includes defederation policies. Just as you shouldn't be annoyed at being banned for spamming (e.g. on the basis of an anti-spam rule), you shouldn't be annoyed at the instance owner defederating (e.g. on the basis of a "no child porn" rule).