> This may sound surprising, but Google has a long history of being a staunch supporter of IM interoperability.

First paragraph is so so far from the truth. Google was a supporter of IM interoperability. Then they closed XMPP interop, and replaced it with their own proprietary protocol. At the same time that they did the same with several other open protocols.

Correct me if I'm wrong, but that's exactly what the rest of the post is about.