I'm sorry that happened and I know you've come back to this several times in your posts. Generally, in my experience, it happens either to new people who don't feel welcome (a plague and an error of a "well-established" community) or to people who are engaged in a debate which is valuable to them and, possibly, during a time of crisis in the larger world. I don't have a solution to that, except that being a part of a community should be hooked onto personal interest, i.e. things one likes to come back to.
One of my favourite writings in fanfic is a thread on a long gone forum of writers/creators about a group of Dwemer coming back to Morrowind right after Dagoth Ur has been defeated. Its so good it deserves to be published

So, I don't know what "Peanuts" are, but I'd be interested in reading that, maybe in the Dune thread?
This generally boils down to the "quality" of what the members bring. I'm suddenly more favourable to the use of proper tags on the forum. Also members should be welcoming to strangers who are brave enough to ask questions.
My first forum was also a gaming forum and it was not as big or as good as CFC, but still had its bright moments.
Interesting idea to take a look at CFC from the point of view of a newbie once in a while. The CFC OT has it, I wonder if other subforums do the same. "Hey, new member, check this thing out to start your stay here" stuff.
As a true Babylon 5 fan, I haven't watched that one
I'd say a deep space port that gets its visitors once every few generations and goes about its business. Human colonies lost hundreds of years away from each other will interact in a much similar way unless some sort of warp technology is discovered. A place to always come back to and to align/stretch out the thread of consciousness over immeasurable space and time.
Sorry if my reply took longer, I am a slow reader most of the time.
Higher risk more or same as any other social media?