I know everyone believes that quest markers are there to hold your hand, and allow for the casual crowd, or kids to succeed in the game... which is strange seeing how kids are freakishly good at games compared to my abilities at that age.

However this is my take. Quest markers give you direction. I know many people get overwhelmed when they start an open world game, and I've experienced this myself. I almost always get burnt out because the lack of direction means I spend hours rummaging through the forest picking plants, or finding new quests and towns.

Can the quest markers be too revealing? At times yes, but at the same time not everyone likes to run around with directions given to you buy a flipping drunk person... Morrowind.

Quest markers do not have to be bad, if they are added after the game is done, so to speak.
So that its possible to play without them.

Quest markers as in Skyrim, where they are an integral part and a replacement for dialogue, is detrimental to gameplay, because it reduces the game to an excersize of follow-the-arrow.

And of course I'm not forced to go to said place, but I already know it's there hundreds of feet before I visually discover it, so the wonder and majesty of exploring is virtually gone for me.