This is something I've always wondered but never really figured out.
For starters, Shadow Priests are essentially the most evil beings on Azeroth. Unlike Warlocks who are inherently evil Shadow Priests will actively forsake the Light in order to pursuit shadow and void magic to deal a great amount of pain and suffering on to others in spite of the cost on their sanity.
Secondly, their actively dabbling in the Void which is likely, for all intents and purposes, the greatest enemy of the game and yet we're not only allowing them to commune with the Void but we seem to be okay that their using what is the fragment of an Old God as their weapon. NPCs will continue to talk about the threat of the Void as the ultimate destruction and even while doing the Priest Mount chain as Shadow makes for an awkward scenario since the Custodian is essentially telling us that they were placed in protection and that the void was eventually going to destroy the chamber... so here you go, Shadow Priest, take these.
I know it's simply a lot of "gameplay for the sake of gameplay" because it's not like we can just erase a Spec from the game because it clashes with the theme but, in a general sense, is there a lore-friendly reason why the citizens of Azeroth allow Shadow Priests to exist but consider things like Necromancy unacceptable? (this is not a new class plug but rather how Necromancers in the game are usually reserved as being outcast bad guys).
Thanks