I've never been an active forum poster, more just a reader of threads. However, I have over the last two years commented on a few threads and/or posted a thread myself. I'm not sure where everyone else has been but, to be honest, I've lost interest since STP12.
You are correct Bill, facebook does not replace a forum but, I think some people are staying in touch via FB rather than the forum. Not that the forum is the place to stay in touch either, it just seems that's where things are right now.
Club Member, Mt Washington Observatory
~ Hike upward and find your Mountain ~