Here is my opinion: most people were not ready for “circles”. A symbolic and geometric understanding of social interactions is something advanced, and hard to preceive. Many understand how society has circles. But many are not willing to accept they are so bias and segregational. read more
Google circles is a classic failure of not attempting to understanding the real user base. Some engineer pipe dream of how they can build something amazing. Google circles failed, because there was a person, that believed in a belief and did not follow data analytical facts. They gambled and lost. read more
Instead, Google+ will become two separate pieces: Photos and Streams. This didn't come as a surprise — Google+ never really caught on the same way social networks like Facebook, Twitter, or LinkedIn did. Technically, tons of people use Google+, since logging into it gives you access to Gmail, Google Drive, and all of Google's other apps. read more