Honestly, I never thought usernames like those existed until now. It's a wow moment. It looks like those early years at BTT were for cruise as most of those accounts aren't any more active. Perhaps they just registered, lurked for a while before disappearing. May be there's a way theymos could clean all that up and completely wipe them off the slate, especially those accounts with zero post. It will be fine to have fresh registrations with them names who will become active.
I doubt he'd do that, as its pretty much laborious and there much better things to do such as countering spam which are part of the mods' tasks.