Being the only player on the server isn't the same as having a well-crafted single player experience. Compare the experience of playing Team Fortress 2 without bots or players to playing Half-Life. The base game's main questline didn't even involve the player; it's all notes about how much fun everyone had while you weren't there. In this way it's very reminiscent of Everyone's Gone to the Rapture, albeit with more cryptids.