Participation stats are, indeed, declining. There is a fairly long-running thread where people complain about the new management and repeatedly claim that the forum is dying.
And yet, there we all still are. The landscape of people changes slowly over time - old hands leave and new hands arrive. Despite the (somewhat justified, perhaps) claim of cliquism, whatever old cliques there were have long since gone and made way for new cliques. Which sort of negates the description of them as cliques, in my opinion.
Personally I don't see much cliquism. It has been suggested previously that this might be because I am firmly in the clique, but I don't see myself favouring some posters over others. There are posters I like and posters I dislike, but these are my own opinions and I don't even know whether they are shared by others except inasmuch as they express their own opinions. There are several posters I dislike, for example, about whom other posters have expressed admiration. I don't feel like there's an "inner circle" consisting of only certain people, while other people are excluded.
That, as I said, is just me, and my view may well be considered to be privileged.