Healers that don't want to DPS are like DPSes who refuse to move out of AoEs.

[Silverquick]

Aoe dps is a bit tricky though, especially in raids. For example in a9s, smn is especially good because they can aoe down the adds with minimal dps loss on the boss (just bane and deathflare), while blm must gimp their single target dps to aoe down the adds by using fire2/flare. Also there are times when you'd rather hold your cds while killing the adds. In short duration and without dps buffs, I'd say whm has pretty good aoe burst (idk how good it is compared to blm/smn without cds though).

Either way the WHM is at about 2K DPS, the SMN is at 4K...

That's a pretty stark difference... not to say WHMs can't DPS... but obviously they are far from the top eschelons.