The different experiences and ideas give these individuals different perspectives that can be valuable and yet these differences can fracture the team by taking the team in multiple directions.
The future is inherently unknowable therefore committing to a final result or plan over a long time frame is fraught with danger as there are too many external forces to be able to consider. Yet teams need a shared goal to create cohesion and direct performance.
The product owner creates a vision for the product backlog. The vision is a description of the desired future state the Scrum Team is going to create.
Unlike many corporate visions that are motherhood statements, this vision needs to be something that can be created. The items in the product backlog will describe how the product owner thinks the vision will become reality.
Having a vision that is affective can help to inspire and unify the team, it can help to shape the behaviour of the team without constraining their creativity. A great vision is one that gets you out of bed in the morning and charges you up for the day.
The vision can help set direction and unify The Scrum Team.