I'm inclined to think they actually understand the potency of AoE, unlike the majority of the community. The damage reduction in Come and Get It is also a testament to this. I believe the community undervalues AoE damage.
In my game the following is entirely possible, fighter pops Come and Get It, followed by Paladin's Astral Thunder, Sorcerer's Flame Spiral, and Shaman's Guardian Eagle Flock. If these powers only catch 3 targets, that's the equivalent of four rain of blows. With a near guaranteed initiative using something like Strategist's Epiphany, AoE's deliver a decisive blow to the enemy out of the gate, which the enemy often won't recover from.
The dev team can be accused of many things, but I don't think overvaluing AoE is one of them.