Why would I ever bring a DRG to a party?

[EasymodeX]

They have the weakest DPS, and their only utility is a piercing debuff that buffs their and archer damage, but not enough to make up for their lower DPS.

MNK has the same amount of stuns, but also has Mantra and more DPS.
BRD has songs, and more dps
SMN has instant res and more dps
BLM has apoc, CC, aoe, and more dps.

Other than a lack of anyone else, why would I bring a dragoon?

According to my calculations, Dragoons have less-than-10%-less DPS than Monks, and they bring the bonus of amping BRD DPS by roughly 10-15%. Not to mention the obvious with MNKs requiring nearly 20 seconds of ramp-up time (negated once per 4 minutes).

Edit:

Oh sup Merix. Trolling much?

Edit2:

Also BRDs should do roughly equal DPS than Dragoons until you add the 57 cooldowns they get access to.

The biggest difference is that BRDs have nearly no rampup time. Combined with the lack of positional requirements or disengage, and the braindead-easy priority/rotation, it's no surprise BRDs are ahead.