i got many bad players in DF.
A PLD that dont know what hate is, all he did was his rage of halone sword skill over and over again. the DRG had to tank bosses.
A WHM that only want to heal with AOE cures because single player cures is "special care".
A SCH that forget to heal the tank cause he's too busy dps'ing.
Players that dont dodge AOEs because "it's the healer's job to keep me alive".
Players who quits the duty in roulette because it's not the instance they wanted.
But most times everyone's good, it's just that the worse ones are so annoying they make you forget about the good ones.