Cool, so it's your baseless opinion vs Google's public stance on their motivations. How productive.
"I, for one, never wanted my YouTube account linked to my Gmail account etc."
I'm sorry that you feel entitled to have Google bend to your will with regards to their high-quality services for which you pay nothing.
Yes, "baseless". You only ignored the other part of my comment, where, you know, I argue about it. How productive (and what an honor in Turing's name).
The reason Google created Google+ are well known, stated officially and have nothing to do with having a single sign on. They could have a single sign on system without Google+.
Nothing necessitates a social forum as a part of a SSO system.
So, there, you have. Feel more productive now?
>for which you pay nothing
Em, I'd hate to break it to you, but Google makes lots of money selling ads targeted to me and other users.