If you read anything on the internet that is remotely related to MMOs, no doubt you have experienced the fanatics, the trolls, and of course the incoherent, oftentimes all neatly packaged into a single person.
What drives much of the flaming and trolling on MMO forums is the close-mindedness of the people. The close-minded fear new ideas that they don't understand, much as young children fear the unknown of darkness. They fear new challenges, because new challenges carry the risk of incompetence and failure.
Some close-minded people are perfectly happy and content with what they've got [insert their current MMO] perfectly willing to stay at their current level of enjoyment because to seek greater levels of fun, to try new games, is to risk dissatisfaction, wasted money, and time.
To have an open mind is to understand that our judgment of a game, no matter how well informed, does not reflect the actual experience, too many variables are involved, too many factors, and too many unknowns, no one is capable of perfectly predicting how they will feel about a game prior to experiencing it.
We don't often see open minded people posting in comments and in the forums, because they understand that they do not have perfect, universal, objective judgment on the topic. No one does.