with the underlying notion that Server 2012 is doing something revolutionary
Not to defend the original AC, but me thinks you did not read his entire post. It opens with: "We used to run linux in the server room because it was lean and easy to admin. Windows was slow, mousy, and dependencies were hellish."
Stating that he claims the new headless developments in Windows Server are new (in general, obviously new to Windows) or revolutionary is disingenuous at best. What I get from what he is actually writing is that while Linux has been moving towards bloat and cr@p, or moving towards becoming Windows-y if you will, Windows has been doing the opposite, trying to become more Unix-y. That is clearly the case, isn't it? Even Linus thinks Linux is bloated.
Microsoft was never a real Server-OS vendor so that they took a while to "get it" shouldn't be surprising. The fact that they are now eating their own medicine (in Azure) probably has a lot to do with it. Heck, it isn't that long ago that all of microsoft.com ran on Sun. Once it stopped, unsurprisingly both IIS and Windows Server suddenly received significant improvements - for those of us who prefer low-footprint server operating systems.