Well, it's certainly a good example of the tragedy of the commons, as I've followed it too for a long time. The only solution that really works requires effort of course - there has to be some sort of curating effort, whether it's a test to get in the door, ending of course with a group that declines from an inevitable lack of attention by human-based forum admins , or what seems to me to work better in the end, have access to a large group and self curate. I'm finding G+ is a decent platform for that, as interesting stuff eventually finds its way to someone I follow. I'm sure I miss some things, but my day is full enough as it is that I can certainly live with the imperfectness.
 I wonder how some sort of AI based system would work here - rather than software suggesting people for me to follow, it instead reads people's postings, private to the group, and public, and reaches out and invites those it finds "fit" the group's focus - sort of a never-tiring forum admin.