Also, seriously, people are arguing about limiting mages in a SINGLE PLAYER GAME!!!!! What is wrong with you?
Exactly. If you noticed, it's not about the balance between different archetypes, it's about immersion. I personally don't care how strong warrior is compared to a mage, or how strong thief is, we're not in MMO. I don't care if warriors get their 500+ damage single handed weapons. This is not what matters. What matters, is the balance of said character vs The World, the game itself. And the ability to interact with that world under your chosen archetype, which significantly affects the immersion you get with your character.
What me, and I guess many others loved in TES games about mages and character development in general? The amount of choices they have, the amount of things they could do. And starting from Morrowind (don't say for Daggerfall, didn't play yet), they're getting constantly cut down on that. From personal experience I can say that that severely reduced the very "feeling" of being a mage, not just fireball thrower.
I remember some of first moments in Morrowind where I started to play as a mage after playing with warrior - it was like "Oh, I can do that! Yes, I'm weak, low hp/armor, easy to kill, but I can do that! and that! (like, skipping part of the dungeon cause I could just make myself levitate. or visiting Telvanni towers, etc)
Not too much left of that feeling. Magic became mainly combat-oriented.