Group buff is essential for dps, no matter what class you are. One of the reasons of why monks are hard to parse well is lacking of proper buffs as what scouts got, such as IA, battle cry, etc.
Until you get 6 fabled set, monk dps on single target is really close to other plate tanks, except sk that is far better than monk.
Basically, don't expect too much on monk single target dps until you are really geared up and get proper group buffs.