@gargron
...like they did with XMPP?
Google talk, Facebook Talk and a lot of other things used to be nicely interoperable. Basically a federated IM network. Then Facebook closed the ports, once they had the majority of users, Google migrated to another protocol, and everyone else except for a few nerds basically stopped it. End of story.

Timeo Danaos, et donas ferentes (quoted from memory may contain errors)