It would be hard to balance properly. Animal morale is already bad: you can scare a bear into wandering near you and taking hits instead of fighting or fleeing.
As for NPCs: it’s even worse, because their relation to player is all permanent. Needs a rewrite, because currently the NPC gets opinion of player at spawn and then keeps it, so player caught naked and wielding a piece of soap will stay un-scary even after equipping power armor and mininuke launcher.
So… maybe someday. It will need to wait post 0.D and 0.D will wait for a longer while (ie. year(s)).