Because it's awesome and much better than the alternatives, which are the 3 elemtals, ash spawn, seeker and followers. Plus it's challenging to be squishy and start a fight without a tank. Unlike regular mages, the longer the fight goes on the more advantages a necromancer has. Plus you can customize corpses, give a regular draugr a shield and a sword and he'll roll be as good as any follower, except who cares if your fireball hits him :p
Because it's awesome and much better than the alternatives, which are the 3 elemtals, ash spawn, seeker and followers. Plus it's challenging to be squishy and start a fight without a tank. Unlike regular mages, the longer the fight goes on the more advantages a necromancer has. Plus you can customize corpses, give a regular draugr a shield and a sword and he'll roll be as good as any follower, except who cares if your fireball hits him :p