My thinking re: closing registrations for a time, is that if currently the only person that can action warranted sitewide bans (e.g. users actively using hate-speech in multiple posts in multiple magazines) is ernest, then there may be a point where there's simply too much to keep on top of, given everything else he has going on.
These concerns may well be completely unwarranted, and I'm well aware that even if kbin.social were to be defederated from a number of instances, that once "the situation" was under control, they could be re-federeated if agreed with the other instances. It would just be a shame to hamper our own community by being relatively powerless against a potential influx of bad faith users whilst ernest is busy being awesome and actively improving kbin as a whole.