February 27, 2015 7:24 PM EST
If you forget the fact that necromancy uses the dead as canon-fodder, it's basically like every other branch of magic. Destruction is an accepted field of magic, even admired, but both good and evil people use it. It all depends on how you use it. If you kill for the sake of practicing or such, then it's a dark practice
As a note, if you use dark soul gems, which is arguably an aspect of necromancy, then your delving into the evil aspect.