valid point. but i could argue the point of warriors as sword swinging barbarians who head to the front of the pack to deal with trouble. why cant i specialize a mage to do that. i just dont want to play the support mage like i did in dragon age origins.
I agree, there is no quick burn high damage direct target line of spells for mages in this game. I can build a defensive caster concept with wards or a shield that can stand toe to toe with the toughest in the game from a defensive perspective but there is no "quick damage burn and churn" spell line for Skyrim. Our best damage per second line for single mob targeting is conjuration.
So, we cannot build a fast damage glass cannon mage concept character in this game. But I personally do not want one

That said, my mage can and does head to the front and stand toe to toe with the bad guy to deal with the trouble. I have a variety of tools at my disposal to accomplish this task including dual casting bolt spells w/ impact, ice storm w/ deep freeze. He can and does wears heavy armor and use a shield but does so rarely currently. I have returned to the heavy armor perk tree and he will be switching his archmage robes for daedric armor soon enough

I have stood toe to toe with elder dragons and death lords staggering them while my Dremora Lord (soon to be lords) dices and slices them.
I have stood in a locked room crawling with undead including a skeletal dragon, releasing ice storms around myself and my trusted Frost Atronach minion intermixed with targeted flame bolts while he pounds undead minions to dust.
I am not a damage dealer, although I can deal damage as needed.
I am not a tank, although I can tank as needed.
I am not a thief, although I can be invisible as needed.
I am not a healer, although I can heal as needed.
I am a controller and manipulator, I am a battle mage, I am a king maker

http://skyrimcalculator.com/#6378
I think my next character will be a spell sword concept. I have to say I miss the mysticism line and the power of the alteration line in Skyrim, these losses have made my king maker concept mage much less versatile in this game.