Whilst its often hard to get players to agree on what the 'most important' issues are that affect the game, there are always certain areas where we, as developers, can benefit from listening to players, watching how the game is played and monitoring player behaviour.

Players will always disagree with some aspects of your game; that's something that you have to accept when designing for MMO games. However, it's also important not to be blinded to genuine issues that the players might raise just because you think - as a developer - that you know better!