May have your reason to decide making getting quest kind of a treasure hunt. You talk to every npc-you get quests, but there is a problem that is quite annoying.
Even when you are questing with your party. It is impossible to announce all quest each member what quest you just got, leading to quest out of sync among party members when you see certain prereq not met, and you are not able to fight certain quest boss together. And it is very difficult to tract back where to even get that quest started to go back on tract.
Maybe this is to make sure players talk to every npc and understand what is going on in the game story, or even better reasons developers have in mind. Well just something annoying I found.