Sundar Pichai, Google's senior VP of products, talked briefly about the decision at Mobile World Congress on Monday.
"Google Plus was always two big things: one was building a stream and one was what you call a social layer... how sharing works across our products and services," Pichai said. "The second one is, in some ways, is an even more important role for us.
"We have entered the stage where... photos and communications are big steps for standalone use cases. We will think of the stream first and then photos and communications as big areas. Internally, we are organizing that way to support that and you will see us evolve."