I've always wondered, what is the problem with necromancy? If it's the zombies, most of the time they're just mindless meat robots, and their former owners are rarely around to really care. The worst I can really see is the economic issue caused by having a bunch of unpaid, mindless, tireless laborers around - and in some ways that could be a good thing.
And anyhow, the root of the word "necromancy" really means communicating with the dead, not zombies.
Well, it depends on the system, really. In some cases, the dead are powered by Evil as a natural force a'la DnD, minor demons running as the body OS, whatever, and in some mythologies, similarly, anything that
will come back from the dead is either evil or just plain pissed off - others will just fuck off to Heaven or otherwise afterlife.
In some others, the dead are not evil, but the process is. Either you're essentially soul-raping ghosts back into corpses or something, or it's not but the way it's done requires immoral means, like, say, human sacrifice or, for Haitan zombies, poisoning someone (some crossover with the first one; in some legends it's sucking souls out through a straw under the house door).
Then you have all the actual stuff being morally grey, but the people engaging in it are predominantly bad, so it kinda becomes guilt by association. I remember a /tg/ story about a good necromancer who essentially had to deal with his mostly senile and metabolically challenged relatives more along the lines of talking on the phone to your grandpa.
As far as IRL stuff goes, the original meaning is very much a cultural thing. It was a normal thing in some pagan societies; Judaism banned that kinda thing to differentiate themselves from their neighbors, Christianity and Islam did it to root out the old faiths' practices, I don't know enough about the culture in other circles well enough to comment.
Hell, oldschool Necromancy pops up in the Old Testament, with, IIRC, King Saul trying to magic-Skype a dead prophet to ask him something or another and succeeding, except the prophet told him to go fuck himself. And of course, around
fin de siecle-ish a whole bunch of people got duped into giving money to mediums, which are pretty much a modern rename.