Yeah... I mean, you don't have to implement everything to be useful as a message platform though... most of the extension usage are kludges anyway. Also, can probably simply use UTF8 and UTC/GMT by convention where the client displays local date/time, etc. Can also revamp a lot of aspects by convention in-network as part of the server/client structures.

That said, I'd still say it's useful, you just need to at least have user/system authentication as plain text over nntp(s|es) to significantly reduce spam.