The "Nice Necromancer" is honestly such a fun character. You get mad scientist vibes, plus playing around with some ethics and taboos.
I remember hearing some argument about how Raise Dead is inherently evil because... the book says so. Which instantly made the conversation a lot less interesting.
Raise Dead is fine, it's the second "become alive again" spell after CPR Revivify.
Animate Dead is the "get skeletons and zombies" spell.
That being said, the various re-alive-ing spells are kind of the best reason for a "necromancy is evil"-argument. Or at least, they used to be.
In 3.5, nothing - not even True Resurrection, which was just "name dead creature, creature pops up next to you, alive" - could bring someone back who had been turned undead, until the undead had been destroyed.
Which means the easiest way to prevent someone from getting brought back to life was to turn them into an undead skeleton and hide them somewhere, nothing short of direct divine intervention would be able to return them to life unless something destroyed the skeleton.
This strongly implied that turning the body into an undead also trapped and enslaved the soul. After all, otherwise, True Rez - requiring nothing but the name of the target, and able to straight up build a new body from scratch - wouldn't fail to rez someone just because their body was desecrated.
Now, in 5e, True Rez says that it can be casted on an undead to return them to life, but also only that it can restore a body "if the original no longer exists", which I guess implies that simply embalming/non-necromantically mummifying the body and hiding it away would also work (since the body still exists that way, and thus 5e's True Rez wouldn't build a new one), making the only notable difference between an undead and a corpse that the undead might not hold still during the resurrection.
Basically, Necromancy went from 3.5's "implied soul slavery" to 5e's "corpse desecration, which is a cultural construct".
See THIS is a more interesting version of the conversation. :P The one I saw was something like, "Raise Dead creates an Evil creature, and creating an Evil creature is an Evil act, per the rules. Period, end of story."
And heck, even without exploring shades of gray morality and cultural constructs, having raised dead trap the soul of the person is more interesting worldbuilding. Even if it's a black & white situation, it drives home who the villains are.
Oh, it also had the [evil] tag, which means that just how a spell tagged [fire] releases elemental fire into the world, a spell tagged [evil] releases pure evil energy, magically making the world a worse place… somehow. For reasons. 3.5 loved to give alignment mechanical effects, it had one or two books (Vile Darkness was technically for 3.0) entirely dedicated to hard rules for morality.
But 5e doesn't have tags like that, and alignment is almost irrelevant. Which is probably for the better, because alignment is incredibly subjective.
Because objective morality makes campaigns easier.
Why are you killing these goblins?
Because they like eating kids. They're eeeeeevvvvilll. Don't think too hard about it.
Of course, the very idea of an adventurer band is based on roaming mercenary bands, and 1st Edition progression was just straight up tied to getting rich with murder. It's just a natural idea to question "Am I the baddy?" once your culture grows up out of Cold War "Greed is Good" bullshittery.
“Raise Dead creates an Evil creature, and creating an Evil creature is an Evil act, per the rules. Period, end of story.”
I understood that as analogous to real-world pollution. The undead are animated by the hunger to consume all life, where the hunger to consume all life is a physical thing. You could put it in a jar. And you could leak it into the rest of the world... Sure, just one skeleton won't pollute the world very much, but it will pollute even if you only order it to do good things.