[u801e]

I've always thought of the main IRC channel like being in a crowded room. You can listen in on various conversations, but if you want to have a conversation with one or more people, you move to another location and converse amongst yourselves either by private message or another (tempoarary) channel.

Threaded conversations are better handled by email or newsgroups as opposed to chat in my opinion.

Edit: Removed extraneous word.