I actually liked Google+ in theory. The idea that you could assign a post to be viewable only by a certain subset of users was perfect. What kept me off was the real-name policy and the lack of third party tools. Slashdot is one of the few places I use my real name online. (This is because I set up my Slashdot account a long time ago and I didn't care who knew my real name then.) I didn't want to link my pseudonym postings with my real name for various reasons - not least of which was because I've been the victim of an online stalker whose potential for damage was limited by her not knowing my real name. However, even when Google relented and allowed pseudonyms, it was in the form of "First_Name Last_Name (Pseudonym)". That doesn't help at all! Why couldn't they let me use my pseudonym and hide my real name. Even better, why not let me assign different visible names to different groups. "Pseudonym" to the public at large, "Real Name (Pseudonym)" to close friends, "Real Name" to family, etc.
As for the third party tools, I would use one application to post to Twitter. Were I on Facebook, I could have used that tool to post to Facebook too. But to post to Google+, I would have needed to go to Google's website. The easier you make it for people to post to your social network, the more posts you will get. The harder you make it, the less posts you will get.