In the case of scrum, the role of the Product Owner is extremely important. In theory, the PO should have both a solid background in product development and business development so that the backlog can be correctly prioritized, in order to make sure that the development team can keep on working on the right stuff without discussions. In practice this is rarely the case and the PO often is just some non-technical person that is assigned to do stakeholder management, which puts additional stress on the team, contrary to the goal of keeping stress away from the team.
