Anytime you set up a message board forum, you try to figure out what will be of interest to people. The whole idea is to try to get people to stop by, perhaps sign up and stay for a while, and if you are lucky, become regulars who post quite a bit.
So you try different things to see what gets people interested and talking. When some things don't work, you drop them and then try something else until you either hit a winning combination or the site goes belly up. Jury is still out on this one, so although traffic has increased, this site surviving is not a given.
I think the attraction of SHTF subjects is that everyone can be an expert. That's because it is unlikely that most of what will be talked about will ever be put to an actual test. And then even if it is, no one is going to really care who was right or who was wrong anyway. Everyone would just be too darned busy staying alive to much care. So acting like an expert doesn't really carry any penalties if you are wrong.
Personally, I have always liked science fiction, disaster movies and novels, as well as anything that smacks of "what if" scenarios. And yeah, I've spent some time on the miscellaneous conspiracy usenet groups just like a lot of other people have as well. Makes for entertaining reading, but you have to keep the grains of salt handy at all times.
So it's basically harmless. If it isn't for you, then you don't have to read it. In the meantime, if it helps draw some traffic here from people who do want to talk about such things, heck I'm all for it. And certainly they will likely participate in the other forums as well.