Well there is sometimes a diff between off topic to the thread and off-topic to the forum.
The latter would for example be talking about ways to grind coffee beans. And that would probably be shut down.
Also, I haven't should down any thread in hours, time to pick one at random
Worst case those interested, can continue by PM.
I am not an IRC user myself. But I also do not get the concept (as far as on-topic stuff goes).
If I would be on IRC, I would not sit in front of it all day long. Like the forum I could only check every now and then.
But by then, a lot of conversation could have happened (If there were many users, which is the desired state). So then, I would not want to read all of it. Where would I get a short overview, if any question/topic was raised on which I would want to participate?
As far as I can see, I would never know. So I would never participate (except if I started a topic / but then someone else needs to spot it).
I accept, that apparently it works for some people. But I haven't got the faintest idea how....