Wut. You seriously think objective markers vs none is a matter of "immersion" and that's it? No difference in gameplay? Jesus I already had you filed under halfwit, may have to be downgraded to quarter.
What's the practical difference between a quest giver giving you an extremely detailed explanation of where to go, vs just having a meta element tell you exactly where to go. There is none. One is a lot more immersive however and makes the game world feel more cohesive.
If NPCs gave you very vague directions that obligated the player to thoroughly explore an area, that would be different. The quest directions in Morrowind are equivalent to asking for directions as a tourist in a city, and having a local give you extremely detailed directions on what streets to follow, as well as marking down local landmarks on a map you have in a brochure.
I like the lack of quest compass/map markers in Morrowind because it's immersive, but you're just sniffing your own farts if you think it changes anything from a practical gameplay perspective.