We Need To Talk, Google
Google is simply trying to unify their services. YouTube was an acquisition, with it's own login system and social network.  They don't want to maintain this separation forever, they want a single signon for everything.Ditto for sharing and contacts. You had separate 'contacts' in Gmail, Latitude, G+, Reader, YouTube, and probably others I'm missing.  Users shouldn't be prompted to maintain N different copies of this information and manage it in confusing ways.It's a mistake to view this as "they're forcing me to use the G+ social stream". It's more "they're consolidating my 5 different profiles and authentication credentials across services."Google could axe the social stream and this would still make sense.