[Rockabye]

That's because people have ridiculous ways of role-playing melee combat. If you really got cut in half you would be dead. A real sword fight would consist of lots of blocks/parries, and direct hits that aren't decisive would be rare. If you're envisioning cutting your enemy in half when they're still capable of fighting, then personally I think it's your perception that's off. On the other hand, you can't exactly block a giant fireball with a weapon. So then why are you doing 50 damage when you attack? You could have scratched or grazed them, or they could be feeling the impact from the collision despite having done their best to block the attack. But no, you are not "cutting them in half," at least not until you've managed the finishing blow.

I don't know if you were around when Evoker was first in the works, so you may not know this, but there is a reason that Evoker damage is superior to the other classes. They are literally classified as "nuke mage." This is likely the primary reason that their skills don't have additional effects outside of extra damage; it's because damage is their gimmick. Other classes have additional effects and versatility in their skills, while everything about Evoker screams "attack with overwhelming power!"

tl;dr: No, no class should be able to match Evoker in terms of raw damage output, because other classes have more room for strategy. For an Evoker, damage is the only strategy. If there ever were a melee class that could move in on Evoker's gimmick, it would need to be something like... surprise, surprise: Berserker.