Even though this issue has been already commented before I support this thread, simply coz spread wing is a total waste of SP. They should change it to make an AoE Stun so you can survive a little bit if a kamael is in the middle of something it will die.
Or maybe an AoE Wind Shackle for that matter, something that has to do with being in the middle of a group, spread your wing that actually happens sumthing ^^
that would be sweet to run away and if they get up on you, spread your wing and stun them all. and when your doing it that purple right wing should appear so 2 wings are flashing out
After some time of trying to work out the use for this skill myself, im afraid i've come to the same conclusion. It really isn't helpful to us in any major way.
Sometimes when suddenly mobbed by lots of easy monsters,i've managed to hit quite a few at a time with it. I've found the damage can be good on lower lvl mobs than yourself but it isnt anything to shout about for the few times that kind of situation occurs.
Worse still if you try it in tight spaces to make the most of it e.g catas or the rift as i did just today all it will net you is more nasty aggro than you can deal with, resulting in an extremely swift death if you aren't careful (god bless body reconstruction!)
I think the suggestion of it having some kind of short stun effect on it is a great idea, i can see the use in making it a defensive "get the hell outta there" skill, I would certainly welcome that.