I think they must consider the IRC network more of a community support service. But it's still being used for general stuff, such as the lounge, trivia games and even my gaming community (#AlterEgo) has a channel there (no need to warn me if you're gonna pull the plug on my channel or bots though. No seriously, I'll deal with it).
Also, try putting Mibbit in a pinned tab while you're waiting for an IRC extension.