The problem with Google+ is that using it felt like work.
It had some nice ideas, and was in many ways better than Facebook. But it wasn't fun, and it wasn't somewhere that was pleasant to hang out for long.
It also felt like it was solving a problem for Google, but not for its users. I could see how it would be strategic for Google to counter Facebook, and how tying searches into my social graph would result in much better data for advertisers. But I couldn't see how exactly that benefited me.
Also the launch strategy of making it invite-only was daft. I was really excited to get an invite just after launch, until I realised that no-one I knew had an account and there was hardly anyone else to talk to. Never really went back.
They learned the wrong lesson from the Gmail invites.
The artificial scarcity of Gmail invites worked better than their wildest dreams. People were selling invites on eBay, trading then, etc. It worked really well to generate buzz. So of course they tried to replicate it. But if you're the only Gmail user among your friends, you can still email them. As you say, if you're the only Google+ user, you have no one to talk to.
I really think the author missed this social point, and it's an extremely important one. As a tech nerd, I had fellow tech nerds who had G+ but I was unable to secure an invite, like many others. It was just frustrating and caused people to develop an anti-G+ attitude before they could even get onto the service.
I distinctly recall a wave (lasted about... 2 weeks?) of serious internet hype where many contacts on Facebook saying they wanted to get on G+ to try and and get away from FB, yet could not get an account due to this rollout methodology. It's my personal opinion this was the shot they missed - you don't keep away the early adopters who will bring in their non-tech friends over time.
Speaking of wave, Google wave too. Really excellent idea, but if you couldn't collaborate with anyone but yourself (because of invites), you aren't really "collaborating" and all the benefits of wave are lost.
In addition to that Gmail at the beginning was a really outstanding offering so people accepted the waiting time. It offered a massively better web interface than practically everyone else and really a lot of storage space. It took other free offerings years to catch up.
The invite strategy did work somewhat while they launched Orkut I think. The major difference this time was that FB was already well established, so artificially restricting access, meant people just ignored it and continued to use FB.
The problem with Google+ is that using it felt like work.
I pretty much stopped using it early on when I realized organizing everyone into the various "circles" was a huge undertaking. At the time you HAD to put people into circles and I had a lot of people from Twitter to import.. so I gave up and just didn't use it.
I like the idea, but the practice of categorizing so many people seemed intimidating and I couldn't be bothered to do it. So I stuck with the alternatives.
It had some nice ideas, and was in many ways better than Facebook. But it wasn't fun, and it wasn't somewhere that was pleasant to hang out for long.
It also felt like it was solving a problem for Google, but not for its users. I could see how it would be strategic for Google to counter Facebook, and how tying searches into my social graph would result in much better data for advertisers. But I couldn't see how exactly that benefited me.
Also the launch strategy of making it invite-only was daft. I was really excited to get an invite just after launch, until I realised that no-one I knew had an account and there was hardly anyone else to talk to. Never really went back.