Except when you have to manage it yourself and something breaks or the infrastructure you have to manage needs managing.
Even if IRC isn't for you, there's XMPP, Mattermost [0], Let's Chat [1], and Zulip [2].
[0]: http://www.mattermost.org/
Just to add, you can use IRC clients to connect to Mattermost https://twitter.com/mattermosthq/status/668898122630721538