Google tried it the other way via Google Wave and unfortunately nobody bought into it.
The main point of the author seems to be that G+ doesn't use progressive enhancement.
I was specifically responding to this part: >A web where re-sharing of content is limited by the platform, not by the capabilities of your client. A web where you cannot comment on an article unless registering in a corporate namespace (which kicked you out if you happened to choose a name they do not particularly like).
The point was that Google tried it open, it didn't work. Facebook is closed, they tried that. Is it working?