I don't know what they were thinking.
They were thinking of every way possible to take away the aspects that made being a Mage fun.
Bethesda:
"...Reduced Spells?
Check!
...Make sure spells don't level with you?
Check!
Remove Spellmaking?
Check!
Enable casting delay to increase innacuracy?
Check!
...Wonderful, wonderful!! Our plans to nerf magic so that the plot-point of Shouts appear to remains relevant are complete."
[As long as magic svcks, so do you Bethesda... so do you.]