Just want to point out the fault with the two bolded statements here: the math speaks for itself.
Take a single pack of 5 chained mobs. Single pack. No double or triple chain pulls, just a single pack that consists of 5 mobs chained together. At this point, MOST DPS jobs should be using their AOE skills. I will use a couple different examples here.
BRD: Mage's Ballad + Rain of Death versus Mage's Ballad + Bloodletter
MB + Rain of Death: 100 potency (AOE) x 5 mobs = 500 potency
MB + Bloodletter: 130 potency (single target) x 1 = 130 potency
RDM: Single-target versus Scatter spam/Enchanted Moulinet
Scatter: 200 potency (Dualcasted AOE; 100 potency per cast) x 5 mobs = 1,000 potency
Enchanted Moulinet: 200 potency (AOE) x 5 mobs = 1,000 potency**
Single-target (assuming Ver Ready procs): 570 potency (Verfire/Verstone + Verthunder/Veraero; single-target) x 1 mob = 570 potency
Single-target (Jolt II; no Ver Ready proc): 540 potency (Jolt II + Verthunder/Veraero; single target) x 1 mob = 540 potency
Single-target (Impact; no Ver Ready proc): 570 potency (Impact + Verthunder/Veraero; single target) x 1 mob = 570 potency
Single-target melee + Verflare/Verholy nuke: 470 potency (Enchanted melee combo; single-target) + 550 nuke (Verflare/Verholy) x 1 mob = 1,020 potency**
**Consider Enchanted melee combo + nuke versus Enchanted Moulinet-- at 90/90 mana, you get 3 Enchanted Moulinets at 200 potency per mob. So, in this example: 5 mobs at 1,000 potency per Enchanted Moulinet for a total of 3,000 potency versus the single-target 1,020 potency.
MNK: Snap Punch versus Rockbreaker; Bootshine versus Arm of the Destroyer
Snap Punch: 170 potency (single target; flank potency) x 1 mob = 170 potency
Rockbreaker: 130 (AOE) x 5 mobs = 550 potency
Bootshine: 140 potency (single target) x 1 mob = 140 potency
Arm of the Destroyer: 80 potency (AOE) x 5 mobs = 400 potency
BLM: Fire II versus Fire IV
Fire II: 80 potency (AOE) x 5 mobs = 400 potency
Fire IV: 260 potency (single target) x 1 mob = 260 potency
The math speaks for itself here. When it comes to a "right," AOE in a "larger pull" (3+ mobs) is the "right" thing to do. The math doesn't lie here. Not trying to argue you specifically, but just saying that you (general "you") can't really argue with the numbers (although I know that some people try to).
Hopefully my math is all correct...double and triple checked everything but I haven't slept in several hours so I'm kinda like @.@ right now....