In summation, I might suggest that while some people might be framing micro.blog as a replacement for Facebook or Twitter, the better framing is that micro.blog is really what you were hoping it might be. It is a traditional web host with its own custom content management system that supports web standards and newer technologies like Webmention, Micropub, WebSub, and pieces of Microsub. Or similarly and more succinctly, Micro.blog is a turnkey IndieWeb CMS that allows users to have a website without needing to manage anything on the back end.
Sure, and in this respect, it’s in good company. As you pointed out, what makes Micro-blog stand out is that it bakes in these newer technologies that enable the core site to extend further than most other options.
Now that we’ve re-framed it to look like what you had hoped for, let’s see if we can talk Manton into open sourcing it all! Then Automattic might have some more competition.
I’m not so sure that open sourcing Micro.blog is necessary to compete. The IndieWeb technologies that Micro.blog incorporates are more significant from the perspective of creating this distributed social web of personal sites. As for competition with Automattic, perhaps a more sustainable goal is to advocate for inclusion of these IndieWeb standards into WordPress Core because those would find their way into WordPress sites, whether they’re running on WordPress.com or other hosts.