So, I'm reading 3e Eberron modules, again, and getting annoyed, again, about late edition design choices. "Late design" might be a bit unfair, since I'm not sure it is happening in 5e, and there was somewhat less of it in 4e. So yeah, 3e is the worst offender.
At low level, you expect to fight a bunch of skeletons and zombies, which can give you a bit of a rough time. As you get to mid-ish level, if there are skeletons and zombies, you expect there to be more of them and, unless there are rule-nerfing amulets to make them harder to turn,* you expect to have an easier time with them.
So there's a progression, and it's built right into Appendix C, where you expect to encounter certain monsters early in your career, and as you gain experience you are either dealing with more of those monsters, or you are dealing with more powerful monsters. So you (a) get a sense of progression, as you begin to have an easier time with monsters that give you trouble, and (b) get a greater variety of experiences which change as you level, because you are dealing with different monsters at different points in your career.
Anti-turning amulets are antithetical to this. When you give these to your undead mooks, you are nerfing an ability that the players/characters worked for, and you remove that sense of progression.
What is worse - and this is a big pet peeve with 3e - is when you make all your monsters nearly infinitely scalable. I'm reading a 6th level 3e module right now, and what are the PCs having to deal with? Skeletons and zombies. But not more skeletons and zombies, which would help with that sense of progression, but tougher skeletons and zombies. So you are still fighting the same number of skeletons and zombies, it's just that the zombies are made from gray render corpses and the skeletons are made from cloud giant corpses, so as to be a "suitable encounter for a party of 4-6 6th level characters."
3e has like 8,000 Monster Manuals and related splatbooks, the PCs are now comfortably into the mid-levels, you couldn't come up with something more interesting than leveled-up skeletons and zombies? Maybe a wight or a wraith for a little variety? I don't know, maybe module designers were asked to show off the monster-upgrading rules, or maybe they use these as (intensely boring) filler encounters because the interesting monsters are relegated to being bosses.
And I recognize that this is a matter of taste, but for me personally, as a design objective of my game, I want players to feel a sense of accomplishment when they level, and have a chance to flex their newfound abilities. They should have the experience of encountering a monster that gives them trouble, to being able to handle them fairly easily, to being able to handle a lot more of them, to sending your troops to deal with them because they are no longer worth the PCs' time. And I want them to have experience the variety that comes with "unlocking" different and more interesting opponents.
Any, that is my rant for the evening.
*Which, given the time and expense of making magic items in 1e, I have difficulty understanding why a necromancer would pump resources into this, when they could just make more skeletons and zombies.