Ah I see what you mean. Well, if you see an inactive tribe you can petition TeamSnapzu to claim it. They won't remove mods otherwise.
Maybe the current influx might prompt them to rethink this. I bet there are a lot of unattended tribes after this spike settles and the Redditors depart.
But how would you do that in practice? I'm sure they have much more better things to do than to trace inactive tribes :). It's the very same way in reddit, if you see inactive subreddit you have to ask for it and maybe they actually give it to you. I don't see anything bad in in it as it is now.