I think it's a little too small now. Anyone looking in who wasn't here from the beginning probably wouldn't join because it's full of threads with "in" jokes and pals talking about things in the past etc. That's not a bad thing.....if you've been here and know the score but for newbies it can be intimidating and a little off putting. Looking at the threads on the 1st page now...where would a newbie jump in comfortably? Looking back...where would a newbie jump in without the accusation of being an ex member? IMO that comes from a few who spoiled it for genuine newbies 
For want of a better word the forum has become "stale". There's nothing exciting that would entice new members in and it's probably why some have left. Not wanting to cause arguments either but there was a hell of a lot of banning that went on that wasn't entirely justified. In that first year we must have lost half the members due to bans. The carry on that happened in that first year IMO set the tone for the forum. How many people got involved in threads back then and how many get involved now? Members that are still here but the only difference is now they lurk rather than post. Complain about the arguments all you like but it made this place come alive and brought everyone out of the woodwork
Add to that people getting jobs, having families etc it doesn't leave a lot