Did Slack ever really embrace and extend IRC and XMPP though? It always seemed to be some kind of hack to get your messages there to begin with.
Slack advocates could say, "Don't worry, you don't have to switch. You can just keep using your IRC client with Slack. Everybody else will have a web UI, which they prefer, and you can keep using Irssi. Everybody wins."
Are we doomed as a community to be surprised every time a company with power squeezes?