What are your thoughts on this? Is the player always right?
I think if both of those ideas be combined it would be what the player-centred design should be.
So The game have to entertain the player, and it is the job of game designer to make it happen. It means that it the job of game designer to think of what aspect he want to put on the game (educational,political,etc), think of what sort of dynamics and aesthetics for it, and do the playtest, especially for commercial games. It has to have those aspects.
It, therefore, could be said that the player always right. The game with more artistic aspect would entertain player more than just a normal game, which is the plus in the game.