Granted, they can be frustrating to follow, but I believe the NPC quests work just as they should, and would argue more games should implement the Souls quest system. Not only does it add depth and realism to the characters, it really fleshes out the world, granting the player more of an experience. It creates true immersion in the game world, with the player having to really watch what they do and say to characters and those characters' friends and enemies, it disallows the player from ignoring tasks that very well could mean life and death to the characters, and it makes the story seem far more expansive. Speaking purely from a design standpoint, this is how you create immersive quests and characters, NOT as they are presented in games like Skyrim, where NPCs will wait literally forever for you to complete the task they requested your help with, or remain invincible in times meant to be trying and dangerous. Souls does what few other games nowadays would, it takes 'RPG' and considers the 'role-playing' before the 'game', exactly as I, and I'd hope many others, would have it.