Because they were pro for this type of play, and they believed its what they wanted. They wont believe anything else no matter how much data supports otherwise. Now that its not working out well they have to place blame elsewhere, they cant look in and say sorry they were wrong. They cant admit it, to themselves or others. This just gets them upset. They lash out, they make personal attacks because using data from the game doesnt work anymore. They cant go off "theory" anymore as the data is rolling in everyday of people not happy with the game, quitting and few staying to play the game.
With the server under populated, systems failing, broken systems, missing systems, and lacking of so many other things, they have no where else to turn but the other players. So they lash out, trying to put some type of blame or draw attention to something else in hopes the magnifying glass will look elsewhere than their failures.