You must be playing a different game. Virtually every quest has a quest marker. I appreciate that the developers included an option in the INI file to disable quest marks, but I tried playing without them for a while and there are some quests were you are essentially required to use the quest marker.
Why? Two primary reasons. One: there are no "directions" given for quests ala Morrowind. You are always simply told "Go here, do this." When was the last time a quest giver referenced the path to an objective using landscape, rivers, mountains or other dungeons/caves? You were commonly told things like "Head east for a while until you see a small grove of trees then look for a door in the hills to the north" or whatever in Morrowind. The other reason: lack of conversation with NPCs to get directions. You used to sort of get in the general area with directions and then be forced to have some dialogue with NPCs (and use Speech I might add) and get more specifics on the location of your quest item/person. All of this is now gone in favor of the quest marker.
What I do now is leave the markers enabled in the INI but don't select the quests in my journal unless absolutely necessary so I am forced to do a little exploration on my own. Disabling quest markers was only half the battle though, they needed to add more directions and explanations to actually be able to have a chance at doing the quest without the marker.
When's the last time someone gave you directions like that, other than some old fashioned driving directions? People don't do that, especially if you aren't following roads and streets. If you were
actually a freelance adventurer in a rugged land like Skyrim, don't you think you'd have a map and compass? Ya.
And if you had a map and compass and Quinn the Quest Giver wanted you to go to her family tomb to clear out some zombies or whatever, do you
really think she's likely to say "Go down the path until you see three big trees, go left into the woods until you hit the funny looking rock, then west pash the purple mushrooms."
C'mon people. No. If her family tomb is out in the woods like that, she's just going to say "Here, let me see your map for a second. Oh yea, right about here."
Some of the people that are wishing for the days of Morrowind's navigational directions based on rocks and plants are just patently ridiculous. That's not how people help each other find things at all.
Here's what I do to keep it fun:
I check my map to see where the quest marker is pointing me, then I uncheck the quest in the journal. I get an idea for where the place is based on the "finger point" that the quest giver gives me, then I go and find it.
That's pretty realistic, and it preserves a fair amount of challenge.