Any serious player could play their Job to the best of its' ability. That goes for tanking and DPS as well as healing. It's the player not the Job.

How many SCH have I seen that leave their fairy on Sic? How many WHM Benediction with full MP? How many WHM Holy until their MP is 0? How many SCH do not understand what Adloquium and Succor is for?

I don't think I am the best WHM, but WHM is my favourite Job and I am proud of WHM. I always do my best to be the best WHM I can be ^^. When in group with a good SCH the run goes extremely smoothly.