You'd have a much better game without them. Most people would hate that though as they would feel lost and frustrated without them. The post above about google maps is interesting; can the average person even read a traditional map anymore?
Not many people remember this, but WoW didn't have quest markers at launch. You basically had to rely on unofficial addons or third party sites like Thottbot back then. I don't think they added them until the second addon in late 2008, and by then they were already in games like Oblivion, Assassin's Creed and Far Cry 2.