In any group I've ever been in, about 5% of the total members make it run, another 10-15% of the total actively enjoy the group, and the vast bulk just stay on the periphery.
In this particular case, my guess would be that they come here looking for answers to questions, but they find their answers in old posts and never post anything themselves.
Another possibility would be that, for whatever reason, they get the wrong impression from the board. Several years back I met a guy at a show with a yellow Challenger. Really nice guy, had a long talk with him. As I usually do we I meet Cuda or Challenger people, I talked up the board. He told me that he had been here before, and that he thought the people were rude and insulting, typical internet fare (this is off the top of my head, so I made not have the details of the conversation 100% right, but I do have the gist of it correct). He did show up here after that conversation for at least one post, but I don't think I've seen him back since then.
