When E added the clone field he posted a comment that I remember about setting a group to inactive for exactly this purpose and he built the clone field to not ignore inactive groups on purpose so that this could be done. So basically, this is the way it was designed to work. I don’t think you’ll see another way to do this.
If you want you could create a custom location rule that you could set so that a group appeared nowhere. I’ve actually done this in the past before the active/inactive setting was added. I find that a group set to inactive helps me fine the ones that are meant to be cloned.
