A few comments:
I've been visiting SimHQ since the late 1990's--not posting too much though.
Back then, the forums were filled with crazy but fun to read people. Now not so much.
The forums were also a go to place for PC hardware news, flight sim news and discussion, and even the site front page was pretty good for getting some info.
Now I only give a quick visit to Community Hall and the flight-controller sub-forum--the latter of which is mostly dead. Community Hall rarely has threads that interest me to even read. No offence, but its an old man's forum in there now.
Since the early 2000's there have just been a constant increase in websites that are just more lively, and frankly, better at providing information than what I used to come to SimHQ for. There has also been a dwindling in the variety of sims and sim related product (flight sims at least which I think made the core of the site in the past). Nothing really new to discuss. Plus the developers host sites that are far better for people to visit who are actually interested in a particular sim (i.e. IL-2 BOS, BOM series, ATAG, DCS home forums). What ends up here is just rehashed news from those sites with no discussion--it occurs at the site of origin.
I am not sure I buy the politics induced theory of SimHQ decline. It is easy enough to ignore. I simply point to other sites out-competing this one in terms of content that attracts membership.