Why is the Monk so disproportionally difficult to play in comparison to other DPS?

[Rapiso]

the damage of the mnk is fine, it only offer that to be honest, no debuff/buff for the raid, and he don't outdamage so much the other class, worst dps class in the game atm imho.

More or less, this.

The problem is that the monk have no synergistic effect with any other class, and if you stack monk, the gain from the blunt debuff isn't huge.
On the other hand, you can make great setup, like X bards + dragoon, or 1 bard + 3 smn/blm.