In addition to having a ton of different ice (or fire or lighting) spells, why not have a generic ice spell that reacts differently depending on the context? If your reticule is pointed on the ground, it casts an ice rune. If it is pointed at a nearby enemy group, it becomes a frosty "flamethrower". If it is pointed at a distant enemy, it becomes an icy spear. If the trigger is held while pointing at the ground, it becomes an icy wall. At worst it would keep most players out of their inventories and quick menus, and prevent them from spending half their time in battle swapping spells. Dual classes like spellswords would greatly benefit.

It sounds like a great idea, but probably wouldn't turn out to well in game play itself. People (A majority) want more practical spells, which is what Bethesda created. Besides, I can't think of anything more convenient than the quick menu. Again, I think that could be an awesome morphing spell, it just sounds like it would be hard to maneuver with in the middle of a battle.

The problem is exact targeting. What if you mean to blast an enemy further away and you actually target a nearby leaf? While resorting to menus and hotkeys is a bit of a pain, it provides the best control over what you want to do when (rather than the game trying to figure out what you want).

Plus, I'd like to think for myself. Why does everything have to go automatically nowadays? What if I want to throw an icy spear on short distance or kill enemies in a big group with it one by one? What if I want to tackle the situation with tactics, and use a spell to for example draw the enemy to a certain place? That just becomes impossible with auto-target.And like susurruss mentioned, targeting will become quite problematic. Imagine wanting to use a frosty flamethrower on the legs of an enemy (when having played shooters, it's advantageous to target particular body parts, so yeah, it's kind of a habit) and seeing a rune coming out.