I think that for many long time posters, who have danced the dance on pretty much every topic, we have now come to our own truths and understanding on how we see the arts and how we express them in our training, and our articulation of opinion.
When that happens, there is less compulsion to explore what has already been discovered by the individual.
I still log on to fullfill my moderator duties, but now if I read someone voicing misinformation, idiocy, or even a valid opinion that I dont agree with, I just dont have the urge to get into it anymore - its enough for me to be able to understand my opinion on the topic, not share it with those who do not wish to hear it.
I used to use the sight purely as a social network for my 'virtual', but very real friends I have made on here, but that element is now catered to by Facebook.
I still get a lot of PM's from members who enjoy my advice on conditioning, and have questions specificaly for me, as opposed to wanting wider opinion/input, and I am always happy to help