You no longer feel powerful or mage like. You know longer feel like you are anything different than the 12 year old's character next door in heavy armor, with one handed and a fireball. Except you feel A LOT weaker. There is almost no incentive to wear robes for mages, seeing as heavy armor can be enchanted with the same bonuses most robes come with and beyond that there is no incentive. The destruction spells don't scale and you end up becoming the equivalent of a snow ball chucking bully by mid game. By then, warriors and assassins are one shotting just about everything and in better armor.
When confronted with a lock, what is my MAGE forced to do? Whip out a rusty lockpick! Why? Because Bethesda took out all the non-combat oriented spells! But hey, at least I can still cast magelight..... However, I'm sure that will be removed in the next TES game, so don't get too attached.
This game has turned into a hack and slash, sorry to say it but that's the facts. And it really makes me mad to see Bethesda alienating the core group of RPG fans that made Beth what they are today.