IOW -the reader doesn't have to leave their comfy Fediverse client, experience or venture into unsafe outside networks or sites with trackers and other data mining engines.
A mission statement? As a decades long FOSS and Privacy advocate, it's really not much of a question to me. My immediate answer is, "But, of course." We should strive for a UX that users will adore. Fact: I love Faceplant - I do! I don't use it, and stay in a galaxy far, far away, but I'm not gonna lie and say it's not one of the niftiest UIs in existence. Everything is smooth and just the right amount of opaque and glossy and smooth scrolling through the stream, wall, timeline, *whatev.
If we make it pretty, then that's going to win adopters from the general public. And if we gain people from the general population.... pretty kewl.
The Fediverse isn't a single, particular protocol powered network - OStatus, ActivityPub, Diaspora, Zot6, Nomad, Etc. #DeSoc is a horizontally scaling, logical network topography. It's the foundational concept that disrupts a monolithic architecture. Both are great, but when you're talking about human social intercommunications it sure sounds a heck of a lot more safe when there's one, three, or twenty seven accounts on a single Fediverse instance than twenty seven hundred or thousand user accounts. I'd argue that with that many active user accounts, you're really accommodating the deprecated, monolithic silo model.
I was successful, very recently, in encouraging a popular sharing service to completely drop the mastodon logo and stop using it. The project lead related to me that of note was the fact that all of the folks who had galleries had different #Fediverse addresses, not half of them actually mastodon addresses. All of the mastodon logos have now been replaced with the Fediverse logo. AND - THAT - IS - AWESOME
