It has been a long time since we had a good airing out on this forum. Sure, some of the best people are gone forever, but they were only part of the equation. Maybe it is the life cycle of a forum for it to peak and then become more of a resource and less of a fun place to visit. Certainly the fact that there is a good alternative forum has had an impact on participation here. I participate in both fora equally, but rarely post the same thing in both.
If rule 10 is part of the problem then maybe it is time to revisit the rules and change what needs changing. I just reread them and find them to be heavily dependent on objective enforcement by the administrators. If they need to be firmed up, or loosened, then this may be a good time to discuss that.
I often disagree with the judgement of one or more of our administrators, but I do believe that this is their house and I am a guest so I live by their judgement when visiting as much as possible. I have neither the technical skills nor the desire to become an administrator. Without moderation of some sort this place would be overwhelmed by unrelated posts about products and political opinions, so moderation is necessary. I believe it could be accomplished successfully with a lighter touch than what we have today, but as I said, I don't want the job.
With some changes we may be able to become more of a fun place to visit. Otherwise, I suspect that the decline in participation will continue.