It's a terrible carrot to get people to actually explore the world.

We will go to remote towns and nooks of the world if you give us reasons, I don't see why we need a NPC to unlock acheivment catagories. Not that I mind, but it's not really what we need in terms of "Getting players to see the world" as that can be the only reason most of these NPC's litter the hamlets and small camps.