It is pretty clear in game though.
If you have a %to hit it's that you attack a target. If you don't you are targetting the ground.
You dont understand me ...
The world is animated, enemies are not frozen, they are constantly moving ...
You are aiming on the ground, in between 3 goblins legs, bcs they are all close together ... you are satisfyed with your aiming, click ... BUT!!! ... exactly in that moment, one of those goblins wawed his hand, or moved his head, or scratched his butt, doesnt really matter ...
SO when you carefully aimed your AoE action, just bcs there are animations, your cursor were actualy over Goblin, rather than ground ... therefore you attacked a Goblin, even if you didnt want to.
(Or vice-versa.)
If you would have some fix way to pick AoE / target ...
Sure, there is still risk that you will be aiming target but instead you accidentally shoot to the ground, for same reason (he just moved when you click) ... but at least you dont compromise your teammates by creating *insert element here* surface instead of attack.
