How is that different from magical abilities?
Though, if they give me better feedback when I'm playing mages, that's just another good reason to use only mages...
With spells, I think there is the mindset that the Mage would need to cast the spell, gather its strength, direct its effect, etc. Mages are more of a mental fighter, so being more methodical fits within the player's mentally established conceptions.
Melee fighting, by contrast, is supposed to be characterized by action, instant and visual, at the second the time to strike presents itself. The "press a button and something awesome happens" concept was aimed squarely at melee combat and the "action" element of the gameplay.
This could be my own pre-conceptions, but that's where I see the difference. The assumption that a player would still want to push a button and have something awesome happen with melee combat would, to me, make it seem like something Bioware might not do.