apples to oranges.
Aiming and dodging skills don't get you anything in wow. It works in FPSs because even though everyone has that rifle, the top people can use it better than the noobs. Everyone can hit lightning bolt just as well as the next guy.

WoW would be very boring if you had 5 spells, only 2 of which you really use. (main rifle, backup pistol)
Games like this thrive on variety.