Yeah google switched hard from promoting interconnectedness to walled garden approach cca 2010. This was in response to Facebook's success and possibility of Facebook overthrowing google as the ad king.
In those days, even Facebook ran an xmpp gateway for their chat.
The rationale at the time was that Facebook had walled-garden chat, Google had to create a walled garden compete. "Copy Facebook at all costs" was Google's survival strategy during the G+ era.
In those days, even Facebook ran an xmpp gateway for their chat.