The Rampant Coyote has a short post on his blog about his philosophy of quest design.
More information.Seriously, it sometimes feels like half my writing & design efforts (in the content phase) are focused on justifying just why the player has to do things in such a convoluted manner. But then I volunteered for that when I opted to make a game series that directly deals with the often weird, illogical tropes of fantasy RPGs.