Well, I understand what you mean OnKonk and in part I would agree with what you are suggesting and it makes a lot of sense but for the fact that as you can see in this product:
https://paizo.com/products/btq02d77?Pathfinder-Adventure-Path-178-Punks-in- a-Powderkeg-CODE
without having the pdf purchased if it is enabled. The same thing happened with this other one
https://paizo.com/products/btq02dso?Pathfinder-Adventure-Path-Abomination-V aults-CODE
however it is no longer available just 1 week ago.