Earlier quoted context omitted.
> If you're an HN user, IRC is probably your usual mechanism for realtime textual communication Mine happens to be Facebook Messenger.
...huh. FBM appears to be a centralized two-way textual communcation system with a strong identity system: It's essentially the anti-IRC. What do you use for multi-way textual communication, or textual communication with weak identity (these often go hand-in-hand)? Or do you just not use either?
You are mistaken: FBM supports multi-way communication. For work, I use Messenger almost exclusively. For personal stuff, some combination of Messenger, Google Chat, and SMS/MMS. I do log on to IRC once in a while, mainly Freenode, but it's far from "primary".
Why does the "average" person ever need weak identity communication? I mean, I'm glad it exists and it has a niche, but why would you expect that to be someone's main way of interacting with people?