"We could be excused for thinking that Micro.blog is like App.net — a Twitter alternative greeted with enthusiasm but that eventually closed...
Micro.blog is not an alternative silo: instead, it’s what you build when you believe that the web itself is the great social network."
Brent makes some excellent points in this post but, as I've said on numerous occasions, App.net wasn't really App.net:
"Most people, even many that used it, viewed the example application, Alpha, as App.net despite founder Dalton Caldwell emphasising it was just a proof of concept. The name Alpha was almost never used."
Just as micro.blog "has learned the lesson that people really like a timeline of short posts" so App.net chose a Twitter clone to illustrate how its "backbone for the social web" would work.
The idea behind App.net was good, where multiple sites and services could all interact via common APIs and feeds (the web as the social network) but became a silo due to the choices made even though this was never the intention.