Slightly off topic but it seems that some evil necromancers have slaughtered entire cities full of people in Azeroth. This is the kind of thing that gives necromancy a bad name.

It isn't the reanimation of bones and corpses that is so bad but using these and their other powers to kill people. Even a 1 HD skeleton is more than a match for a 1st level warrior. When your raw materials are the bodies of those killed then it has got to make people a bit wary of you.