I noticed the traffic slow down over a year ago in the NPHC forums. When I first joined GC all 9 forums had active threads throughout the day. Then it trickled down to just the DST forum, and now that is even kinda dead.
I think there are two reasons:
The first: there are just so many other social web sites that people can use to communicate.
Second: I feel that some regular posters have made it near impossible to come here and enjoy a casual chat in any forum. I mean, there are regular posters here who will take what someone says and split hairs on just one word, phrase, or meaning. In the early years of GC you did not have to worry about beaing soooooo politically correct. Now you do.