Saying that a MNK will out-dps X job every single time is incredibly ignorant. There are many fights that favor ranged dps over melee, not to mention that people seem to overestimate MNK dps to begin with.

Essentially, there is no fight that 'requires' melee dps, so why use it? Sure you can use melee dps in coil groups that don't suck, but in PUGs, you might as well use all ranged to lessen the chance of failure.