Sadly, we don't even invent new protocols any more, at least not open ones. What we do is invent new, closed platforms like Slack (and HipChat and Campfire before it).
Besides the obvious hype and hipster “this time its different” appeal, is there any technical reason one would would prefer Slack over, say, XMPP? I looked into it only until I realized one has to pay to access chat history.
Slack gives you a unified chat stream and a simple, buttery-smooth onboarding process for the tech-naifs. Jabber does neither of these. I'm not fond of Slack in particular, as it's ridiculously expensive and the main chat window is too widely spaced, even with mods.
I use jabber with a friend, and frequently messages go to his other laptop, which he doesn't see until he logs onto it. Same in reverse. Similarly, history isn't unified. You can get around these problems by having your own centralised jabber chat client (like bitlbee), but that's a technician's answer, not an answer for the general public.
And >90% of the cases detailed here are covered by an IRC server with TLS and certificate authentication, and you can even use it on a mobile device with the kind of humane, task-focused UI that a general-purpose SSH client can't provide.
