Animal Crossing isn't all that fun. It's consumerism in a game form. You spend your time doing menial tasks so you can get useless material possessions and pay off your increasing debt. And while you may speak to your neighbors you never build any deeper connection with them, your life is solely defined by the stuff you have acquired.
Of course a sequel could potentially diversify the game play in order to make it fun for more than week, so I am not going to say a sequel would be a bad thing.