OK, look: the other people who responded about orher systems Google had that had other login systems (hours before you) were both constructive (showing specific examples) and general not jerks about it... They also kept this thread about SSO on topic--jmillikin specifically states "unified login/account system"--nor did they then decide to respond this negative without any real argument. The whole point of this Ask HN was that a bunch of us dislike G+, but the goal was to discuss the reasons why G+ was being pushed internally at Google, and some people from Google were nice enough to actually respond, so let's do away with the random "service geared at destroying anonymity and privacy" rhetoric for a minute.

So: I'm sorry. I did mess this one up. I don't think, however, that my mistake was actually important from the perspective of the article. I've been using some of the services people are saying had third party login support now for many many years, and unlike YouTube I do not remember ever seeing any kind of disconnection between account models used on each. Maybe they were just integrated faster, or maybe its because I had a YouTube account that was ancient and had options that others long since did not.

But either way: it doesn't seem like SSO is an argument for Google+. Google already had single sign on, and to the extent to which it ever had separate login systems that it maintained for its acquisitions they were all rapidly merged. Maybe even in the case of YouTube (which I still feel was different, give that as recently as a year ago I remember still having the ability to manipulate my underlying YouTube account).

Forcing the account to use G+ does make it get forced to use the underlying picture and name from the other account. I can see that as being vaguely interesting. But that goes beyond a "unified login/account system".