@0x1C3B00DA That's only one of two options. The other one is that you can use a nomadic identity with different servers, so that those can still be focused on a specific thing, but you can use the same account to post to say a micro-blogging network as well as photo community, or some Lanyrd-style event calendar site. All of them need moderation, and I also wouldn't want to lock people's entire social life into one server that they probably signed up for on a whim.
@0x1C3B00DA Also, "has held back" is a bit of a strange argument, considering that ActivityPub is not even half a year old and we have all these implementations working and being used already. Even if it's not a generic AP server, it certainly has done more for AP adoption than any other software, being the first implementation at all really.
@0x1C3B00DA I see your point, but as far as I know Pleroma is doing C2S as well as S2S and they're planning to make it more generic in the future. Every implementation has to be tested with others still, because the AS formats themselves aren't standardized (yet?).
@0x1C3B00DA ActivityStreams standardizes the general format, but not the actual post types etc. There's https://www.w3.org/TR/activitystreams-vocabulary/#object-types but it doesn't contain a good match for microblog posts. They're neither articles nor notes. Problem with these specs is that a lot of the content comes from theory, not implementing software. Hence, they cannot cover real-world usage very well.