ap master yi is still just as much a carry, i usually get somewhere between 15-30 kills every game, and as for turrets i guess its true that you cant damage them as much but during meditate its kind of funny, you can actually tank a turret for other people.. very useful when the turret has low health and you need to take it down

Very....ehem... Veird bulid...but
- Some of Hp to survive
- reasonable

Anyway you are treated as a carry. Without you, probably there can be problem with turrets.