Even I love G+ on principle, but that's the point, in principle. The problem with G+ goes deep, first of all, they just assumed that a network gets traction because of beautiful UI, it is not the case, if you look at facebook's growth, it started as a way to talk and later as a dev platform, because of farmville and games like that they get a lot of traffic, so essentially facebook means different things to different people.
When fb came into existence there wasn't much of a competitor to it, so they focused on making it easy to use and stuff, later, when g+ was being created they misread the entire picture. At that point fb had become a platform or was becoming a platform. Currently, FB has different users, some use it as a buy sell group, some for messenger, some for playing games (APIs) etc
g+ didn't focus on good things, just beautiful UI doesn't mean you win, you have to differentiate yourself, they should have gone this way, start a private beta, build a terrific API for developers, so devs will flock to your platform and build apps on it, plus the circles stuff, it is great for geeks like us, but not so much for my grandma, who doesn't even know what google means. Plus, g+ takes an awfully large amount of time to load on slow network. Overall. Plus they don't have an end vision.