Why does it seem like these are nunu nerfs?

Nunu

Ice Blast (E) 
    Cooldown lowered to 6/5.5/5/4.5/4 from 6 at all ranks
    Mana cost lowered to 70/75/80/85/90 from 75/85/95/105/115
    Damage lowered to 80/120/160/200/240 from 85/130/175/225/275
    AP Ratio lowered to .9 from 1.0
    Movement speed slow increased to 40/45/50/55/60% from 20/30/40/50/60%
    Movement and attack speed slow duration lowered to 2 seconds from 3 seconds

lower cooldown at max rank but the slow and damage and ap ratio are all worse? I would rather just have the expensive cost snowball instead of some low damage low duration cc.