Not always there were a lot of quests that just give you vague instructions without a way point showing up.
Just the way I like it!
I'd take incredibly vague instructions over precise pin-pointed locations without any dialog leading up to them any day.
Skyrim:
"Retrieve [X] for me please, some bandits took it, I'll reward you handsomely." - You magically know where it's located.
Morrowind:
"Retrieve [X] for me please, some bandits took it to a cave south of here. Have fun looking around for an hour and finally finding it."
These are pretty exaggerated examples, but good indications nonetheless. I know which one I prefer. I feel no need to powergame myself through TES games and finish the quests as fast as I can. Morrowind's version encourages adventuring a lot more.
Besides, they could always make exact locations toggable on the map.
More options > Less options.