When you go beyond page 5 in other forums, either people say what they think without arguing, or those who argue get involved in an argument that no one pays attention to, often going off topic.
There are campaign managers who may start ignoring your posts if it's almost only you discussing in a topic.
And yes, there are the many who just post something and move on.
These are both problems of the signature campaigns.
And I don't even talk about the "past page 5" area which in many cases becomes a meaningless mess.
But in a discussion it's good to wait for a third person's answer too sometimes, in order to prove your or thee other guy's point.
Or sometimes you or somebody else give the right answer and one simply doesn't have anything to add there.
And then instead of a not-really-valuable "You're right", people just move on, leaving topics look unfinished (although sometimes the merits on a posts tell the story).
So there are various cases and you seem to not care much into differentiating them in order to find some good directions (or even answers).
I tend to believe that Poker Player is right on this, especially as it's not the only topic you've made under this same format lately (I'd be happy to be wrong though).
Wait, there is? Like the same kind when you suddenly remembered to post on a thread that you left hanging and then there's the red "Your session has timed out" text thingy?
If you write into an old topic, you'll get a red "Warning: this topic has not been posted in for at least 120 days." message on top of the edit box.
Indeed, there are some debate there now and then, or people can easier correct one another. Good point.