Hi blowerbee !
Players scores and ranking statistics are always useful for you as a developeur in order to balance your games.
But it is not always an important feature for your players, it depend of your game type.
If it is a social and skillful game, it will be an important feature because all your players will try to play again in order to reach their friends scores.
If it is an ambiance game with no stress, scores are not the main objectives of the players, they play your game because it has a good atmosphere, graphics, story line...
It's my own opinion =)