Well, if you think that the mean age when they registered was around 15, and that was ~5 years ago so now they would be around 20, and they'll have university, or work, or boy/girlfriends to worry about, not?
Don't forget about "generation" of people who registered on the new forum, for the first time, as well as me, Bender and a few others, who registered on the old forum, not so long before it was closed.
O_o
wat?
If you have girlfriend (or wife), you forget about forum?
O_o
Lol, wut?
No, but if you are with someone it's evident that you have to spend time with them. And that time has to come from your free time, which includes the forum.