I'm having a troublesome time understanding why the animate dead spell is considered evil. When I read the manual it states that the spall imbues the targeted corpse with a foul mimicry of life, implying that the soul is not a sentient being who is trapped in a decaying corpse. Rather, the spell does exactly what its title suggests, it only animates the corps. Now of course one could use the spell to create zombies that would hunt and kill humans, but by that same coin, they could create a labor force that needs no form of sustenance (other than for the spell to be recast of course). There have also been those who have said "the spell is associated with the negative realm which is evil", however when you ask someone why the negative realm is bad that will say "because it is used for necromancy", I'm sure you can see the fallacy in this argument.
However, I must take into account that I have only looked into the DnD magic system since yesterday so there are likely large gaps in my knowledge. PS(Apon further reflection I've decided that the animate dead spell doesn't fall into the school of necromancy, as life is not truly given to the corps, instead I believe this would most likely fall into the school of transmutation.) PPS(I apologize for my sloppy writing, I've decided I'm feeling too lazy to correct it.)
Fundamentally, that answer is going to be Doylist: D&D wants to have the general trend of playing into fantasy tropes, and those are going to include the big bad nefarious necromancer and their army of undead minions being the villain against which the PC heroes will tend to fight. There will of course be campaigns where the PCs are the traditional 'bad guys' (and yes if all they do that is 'bad' is use an army of skeletons and you don't see that as evil, they may be 'bad in name only,' but you can still probably recognize the theme). Likewise, there might be a game world (
cough, Eberron) where undead and their use aren't inherently evil, and hopefully some level of examination of what that would mean to a society. Those are always going to be the alternative interpretations in the same way that all other subversions have to be (ex. your 'what if the things that look like angels are actually the bad guys and the things that appear to be devils are the good guys?' story only works if that is a violation of the expected).
If you're looking for an in-system answer, you're going to run into multiple problems. The first is that D&D ethics and morality has always been absolute hash. Good and evil are generally 'you know it when you see it' and when it's really not clear whether something is or isn't one or the other, the actual rules have never been great guidance (
especially if you are also trying to marry it to any real world ethical framework). Given some of the stuff that has been put down (be it Gygax's position on orc babies or killing surrendered foes, or the 3e alignment books Book of Vile Darkness and Book of Exalted Deeds), sometimes it's best to leave well enough alone, or to impute your own preference instead of relying on the books with regard to alignment.
Even beyond that, real world ethical frameworks (by which I mean either the spectrum of ethical schools of thought generally lined up as running from pure deontology to pure utilitarianism and everything in between; or the broad brush categories of beneficence, non-malfeasance, respect of autonomy and justice) also kind of struggle to explain why something like this would be evil. Especially inherently, and super-especially if you put in enough contrived qualifiers like Aunt Gertrude wanted to be useful after she was gone and there's a social system in place such that this isn't a way for the mob to dispose of murder victim bodies and so on and so forth.
D&D is this weird place where independent adventurers wander around with the power to level villages, inject themselves into situations where they often act recklessly and without complete information, and generally are still considered more trustworthy than a political ruler or society that is using traditionally evil tropes like undead or lycanthropy or whatnot for benign purposes (and more often than not they are right, because it makes for a more compelling adventure that the town with the undead workforce is secretly about to be devoured/about to go to war with their neighbors).
A
murderous bucket with arms and legs that will try (hilariously) to murder you when inevitable oversights happen.
After Scruffy rejected
her, she went on to do the only thing left that gave her existence meaning--murder!