It's not just about the numbers though. It's about predicting what would happen if they lifted the locks. Leviathan has never really had the same level of player zeal in trying to get on to the server as Balmung and Gilgamesh. As long as the strong possibility exists that people will just rush the opened servers (which the many threads like this basically indicate) then it's highly unlikely the locks will come off until active player populations have reached near irrecoverable levels (not "stagnating" or "choking" but actual bottom tier, near dead world levels)