I am maybe alone with this opinion, but I do only understand how to apply Scrum in an organization, if I add 3 more roles to Scrum:
The Customer – He orders the product. He pays the money at the end.
The End-User – He uses the product. He is the only one who really knows how he uses the product.
The Manager – He builds the organization, is responsible for stability and training of people.
I do need to distinguish these roles to be able to understand the dynamics of a Scrum-Team in an organization.
By using these three roles conceptually you can solve most (I do not know all questions) questions of organizations about Scrum.