You don't need to cancel the rank. Just get rid of Junior signatures completely and only let them have a signature until the achieve Member rank with ten merit. Junior rank still has its place and I think the one merit requirement at least sets them apart from the worst or the worst of Newbies who can't even get that. Let's make them step it up before they're allowed to earn by posting here though and ten merit is a good aptitude test for that.
Yeah, this would be nice. But, judging by themos' words he doesn't want to add too many restrictions, and this one would likely be a little to harsh in his book. I support the idea though, especially if this current solution doesn't prove beneficial in a few months time. I guess this would be the final draw until removing signature campaigns themselves. Imagine the uproar in Meta if that ever did happen.