This is horribly biased, no single role knows more than any other role. It is purely down to the player and only the player. Everybody has a job, whether you do the job well is the players fault. An example being I was doing a low level roulette and this bard kept on pulling off the War (who was still new and didn't know optimal rotations) and he got horribly offensive when I told him he should slow down his DPS, yet it is entirely his fault that he pulled. Some players are either lazy, conceited, or stupid.