I think the problem is that so few people even understand the need to connect people to the main tree. It seems like every week, somebody starts a thread asking what "Unconnected" means, because a 568, 569, or Unconnected category has shown up in their watchlist.
I will admit that I haven't been watching the unconnected categories that I normally watch lately, because I've been chasing off on other projects. At one point, I had the British Columbia Unconnected category all emptied out, but now I see that it's filled up again.
I agree that using EditBot to remove unconnected categories from profiles once they're connected would be a great idea. It would save time for connectors who go into a list to try to clear it, only to find that bunches of people in the list are already connected.
I didn't create the unlinked category, and I don't know who did, but I do think that it's important to be able to find completely unlinked profiles.
If I remember correctly, the last database dump you sent me listed about 2.5 million branches with a size of 1 (which would be the unlinked profiles). Since the total unconnected profiles are about 3 million, that means that roughly 5 out of 6 unconnected profiles have no connections at all. If we're going to bring down the total number of unconnected profiles, at some point we're going to have to address those. (Personally, I think a challenge/connect-a-thon would go a long way towards addressing that problem, but I have absolutely no ambitions to try to run one.)
That said, I don't know that it's necessary to have an unlinked category. If you created a suggestion for profiles with no links at all, that should help identify those profiles with a lot less manual effort. On the other hand, if 2.5 million profiles are going to be too many for a suggestion, then we can stick with the categories until we can get those numbers down to a more manageable level.
I will say, though, that using EditBot to move people out of the unlinked categories into the unconnected categories once they have a connection to at least one other profile makes a lot of sense.
As for the unconnected notables categories, I can see replacing them with reports, something like what you did with the unconnected profiles. Just let me know where to find the reports, give me a couple of weeks to replace the links to categories with links to the reports, and then you can move all the unconnected notables into the normal unconnected categories.