With Chatsubo, what's the history there? Seems like a SF dominated board, right?
I believe a typical answer to this would be complicated and flammable. In short though, Chatsubo is an old board which had its roots in some kind of attempt at mediation between rivals. Thereafter it's played host to countless flame wars and such things. Plenty of people disliked it immensely and popularized their opinions to a degree that a lot of people figured there was only nastiness going around there and ignored the fact that a lot of very good discussion was happening there and for a very long time.
Many folks also considered it to be SF dominated so that would be the word going around, no doubt. It was frequented by plenty of their folks as well as being moderated by some of them. The moderation was light in touch however and while I'm sure someone will come raging with a counter example, but I feel it was done quite well overall. The mild moderation did allow for a style of witty sniping and snarky commentary from many folks which did in fairness turn off many people.
My guess is that it will die away now, though. Right now, I view it as an archive for all that good stuff. Where all that stuff goes if it not only dies away but also goes away from the 'Net is a very good question indeed.