I was definitely attracted to Google Plus because of the ability to discover people who I did not know. Of the thousands of people who signed up for the Scrivener Users community, I am sure that I did not know 99% of them on the day I started that community.
One of the main reasons that I continue to engage on Cake is that I can communicate with people who are not known to me about things which are of mutual interest.
Incidentally, I liked the G+ as a hub strategy. I liked having a URL for a profile page in the original (2011) G+ platform, in which I could provide more information to people who I trusted. Less information to those with whom I was acquainted and even less to the general public. I liked being able to decide between public postings, circle postings and topical postings (Communities and Collections)
The one thing that I did not like was that Google seemed to be more interested in growing the number of G+ accounts than it was in making certain that people understood the difference between the FB "friending" paradigm and the G+ "broadcasting" paradigm. To many people left G+ out of being confused about how it worked.