I haven't been on here for long enough (believe it or not!) but I do vaguely recall this place being (a) a lot busier, and (b) a lot more full of aggressive idiots. Both seem to have largely departed.
Where have they gone?
They haven't gone to Usenet, which (on aviation) has suffered the same fate in terms of traffic; in fact much worse.
A lot of them have probably gone to the Flyer forum, where they have great volumes but the average quality of posts is as dreadful as ever, and most of the top posters write drivel.
Maybe this is a wider problem?
I've been "online" since c. 1995 and back then Usenet ruled the roost. It remains the #1 technical resource for software and hardware development. However, "discussion" has moved to the WWW (presumably because nobody knows how to set up Outlook Express for usenet) and now there are thousands of WWW-based forums. Everything seems to have a forum these days. Even an obscure brand of a tablet computer has its own forum - even though it is largely ignored by the manufacturer and is thus next to useless.
However, I am not aware of any UK oriented aviation forums where the ex pruners might have gone. There are a few others but they are quite obscure.