I'm going to take a plunge here and say:
I also feel that the quality of the forum has gone down.
I think the forum got off to a whizz-bang start, there was lots of dialog going on and interesting stuff learned.
But now, I notice more pointless quarreling and negativity on board...and it seems it's because - dare I say it - most of the forumers are pretty young.
Take that in the right light: I'm not blasting the forum because otherwise I wouldn't still be here, albeit less often. I chose the threads I read more carefully and pick my replies because those take time.
But I see it for what it is, and I get what I want from other forums online. There's an abundance of choice; and if this forum doesn't rock your boat, you can probably find one that does.
And if my opinion is in the minority, I guess that makes
me the freak here, so
there 
nyah nyah
Either that, or I've changed since the launch of the forum - which makes it even more interesting.