My two penn'orth on the changing nature of these forums....
10, possibly 15 years ago, our access to information was mainly face to face, or via reading books & magazines. If you wanted to know something you asked people or went to get-togethers where people presented & talked. I have some "old" (early 90s) editions of the PFA magazine and the amount & nature of the information in them is vastly better than the "sound bite" stuff we get now (Sorry BH if you're reading, Light Aviation is still a good read, but the old stuff is just directed at a more understanding audience).
I can equate this state of affairs to my area of business, computing, where we used to meet up every quarter & be presented with the latest & greatest technology news by experts just back from the US.
Then in the late 90s we had the explosion of the internet, and people published data there. We no longer needed to wait for the meeting every quarter as what we wanted was posted up on web sites. In fact we saw the information at the same time as the "experts", and the expert became the guys who could read the fastest.
Move forward into 2003 onwards and we get the rise of using social networking, like forums. Everyone can contribute and they do, you end up with an active place like PPRUNE where the knowledge & experience can be shared. Now, not only can I get information from ROTAX web site about the 582, but I can ask other people who share their experience.
But of course all that experience gets stored away, and now we have these super search engines. If I want to see the collected wisdom on the Rotax 582 I can ask Google or Bing and then collect the postings from the previous 10 years.
We don't need to interact now because we can find most of it already. All we have left now is "News", and that comes at us raw as it happens.
I guess its inevitable that places like these forums slow down, not necessarily because a lot of older pilots are walking away from flying in general but because their voice isn't being heard now...which is a great pity. We all think we're experts now, yet the real experience & expertise is actually in danger of being lost.