From HN-user whatshisface's comment:
If the reason for "not forcing them to handle content from server Y" is that the admin of server X had a name calling spat with an individual user on server X, the fact that the fediverse makes instance admins into miniature dukes and dutchesses, complete with wars and Honor, is an unalloyed pain. ;-)
I think this user is saying this as a negative but I really think this is an advantage of the Fediverse and an intended consequeunce.
I don't think I'm alone in thinking that I'd rather have dukes and duchesses ruling little fiefdoms in the fediverse over King Zuck, King Spez, King Musk who have full control over their respective network. Each can have their spats over stupid stuff, but in the fiefdom model, with a little technical knowledge you can make a part of the network you have complete rule over, and engage in something akin to diplomacy with the other little fiefdoms.