Kayle has been nerfed a lot during Season 4, both indirectly and directly. Q ratio nerfs, E ratio nerfs, R cooldown increase and Lich bane ratio nerfs.
What are you going to do about her? At least Jax after his nerfs received some changes about his early and late game, where is early game got nerfed a bit but his late game got buffed in tankiness.
Is it possible that the same thing could happen for her? (i am not talking about the tankiness,i am talking about how she scales) Right now she's a lane bully during the early, early levels (just lv 1-2), and then she can't trade to almost anybody and before she reaches a good point she needs 3 items (nashor's, lichbane, rabadon/zhonya): this part is just too late in the game.
Kayle was supposed to be a late game damage champion but right now her utility holds riot from buffing her damage. (since when they buffed W and added a movement speed scaling with AP, increased her W ap ratio and removing R mana cost)