When they launched all the talk was focused on the social network. The focus should have been on the primary product which is that they introduced an account system. The social network just simply came with it for free. You could use it or not use it.
Google accounts meant you no longer needed to use your Gmail accounts to sign up for Google services.
Could bind everything, Gmail, any other Google services all to the same Google account. When Google then pushed to get people onto the new accounts system people thought Google was trying to shove the social network down their throats.
The social network again, though was secondary to the account system. Google+ likely would have been better received had people been properly informed on the benefits of creating a Google account.
http://www.forbes.com/sites/kashmirhill/2011/08/29/googles-e...
http://blogoscoped.com/forum/164385.html
http://www.computerworld.com/article/2517360/security0/repor...
The "G+ is just an identity layer on top of Google" was a common soundbite reported by executives at the time, and perhaps they even believed it, but my engineers-level view as someone who worked with the G+ codebase was that this was mostly marketing speak to differentiate us from Facebook and deflect criticism of "Well, if G+ is a new social network, why would I use it over Facebook?" By saying it's the identity layer for Google, they can then say "Well, you use Google already, this is just the social layer that ties all Google products together." On a technical level a "G+ account" was just a bit set in your Gaia record that indicated whether you had opted in to G+ features.
Then again, the guy responsible for the mess was an ex-MS exec that continued the mentality of mentally tying his fief with everything else. Sadly Google is taking forever to untangle the knot (likely because it is unsexy maintenance work).
For a brief moment, I thought Google had a chance with Google+. The discussion model is better, the moderation tools are better, but it just doesn't have the users. I wonder if they had launched with a read/write API and good developer libraries, would Google+ have achieved critical mass? I'd still love to see Google try this since they really have nothing to lose at this point.