IceFrog isn't the best balancer no - but he makes sure all heroes are viable. I remember in DotA that you could just about play any hero and actually be useful.
Plus, he is also pretty inventive when it comes to new heroes and items. I can't wait until DotA 2. I've been missing my Tiny and Morphling
Also: a lot of heroes in LoL are copies from DotA with their skills dumbed down.