> people aren’t going to go out of their way to setup “bouncers” to keep up with conversation that happens when they’re not online

As an avid IRC user, Nor am I. My favorite thing about IRC is that there's no expectation you "keep up" on conversations that happen when you're not there.

Hell, my client barely even keeps track of notifications. The tab for a channel will color red if someone mentions my name, but that goes away as soon as you open the tab. No need to scroll up to where you got mentioned if you don't want to.

The ephemeral nature of IRC makes it a surprisingly relaxed experience.