See, you're wrong.
Go read the comics
He has commented that he felt that an Enchanted Magic Sword felt as if the sword was made of Kryptonite.
He has been blasted by countless amount of Magical Blasts or Magical Lightning Bolts and been wrecked by it.
Hell, one time a guy just Enchanted his Fists with Magic and was able to easily beat Superman.
It's not just Abstract Effects, if the source of the Fire is Magic, he is weak to it. He will probably react to it as if that Fire was a blast of pure Kryptonite.
The difference is, in that universe Magic is pretty incredibly rare.
In this universe... EVERYONE HAS MAGIC.