When AZB was started 20 years ago, there was no Facebook or other social media type sites. There were only forums. I think most people probably only joined one or two forums, so a lot of them had a "non forum related" section for their members. Today, maybe it is not needed, as there are probably a bunch of FB groups specifically for politics one can join and argue to their heart's content.
One thing with "groups" on FB, is there are thousands of them, and they each have a specific topic. Not a single one I'm in allows any political discussion. But with FB, you have access to any topic you want by joining a group on that topic. With the old forum style like AZB, it wasn't like that.