@applejack
I understand and appreciate the journal experience. My issue with that approach is strictly with how I usually end up playing a game.
I often will have periods when I get bored of a game, and do something else for even months on end, and then randomly want to go back to the original game I was playing. At that point, no journal will be able to get me to remember where I was, where I was going, what NPCs and from where gave me quests and so on. I'm basically at risk at being completely lost and abandoning the playthrough or the game entirely.
For better or worse, map markers help mitigate this for me. I've got a Fallout 3 playthrough I modded a year and a half ago, and played less than two weeks before pausing. This week I randomly decided to play again, and was able to pick it right up immediately.
@applejack
Map markers, especially how Bethesda does them, have plenty of flaws too. A lot of times a combination between map markers to show a general area or zone, and a journal description to describe something specific would work sooooo much better.
But if I have to choose, my balance does tip in favor of map markers, for the assurance that I won't get lost in a game just because I don't play it daily.