I'd rather they did a compromise wherein we get both a Witch lifestate and a Magic skill for everyone to learn, not just Witches. There's already a similar structure present in Vampires, where there is a Vampire lifestate and a separate Vampire lore skill that everyone can learn, but vampires get the most benefit out of it. Having a separate Magic skill can be far more beneficial (and more superior) for Witch lifestates that naturally have magic in their veins than say some random Sim trying it out.