Because the nords now are not the nords of old. They have forgotten their high regard for the Clever Craft.
But isn't that a little weird? That's like all of the orcs saying forget the old ways lets become mages. I think some lore was left out because none of the nords mention their ancestors using magic or why they don't follow in their footsteps.
Nords are also staunch opponents of Julianos, historically.
I will have to do some research on this. Thanks for the info.