The Developers need a Sprint Goal because it gives them a common yet specific goal to focus on during the Sprint. This is because:
* The Sprint Goal is a short-term objective that provides guidance and focus to the Scrum Team throughout the Sprint. It is a flexible and negotiable commitment that can be adjusted as more is learned
* throughout the Sprint.
* The Developers are accountable for creating a "Done" Increment in every Sprint. They must ensure that every Product Backlog item they work on meets the Definition of Done before it is considered complete.
* The Developers are self-managing professionals who organize and manage their own work. They decide how to best accomplish their work, rather than being directed by others outside the Scrum Team.
* The Developers need a Sprint Goal to align their efforts and collaborate effectively as a team. The Sprint Goal helps them prioritize and optimize their work based on value and impact. The Sprint Goal also helps them cope with uncertainty and complexity by providing a clear direction and a shared purpose.
Other options, such as a Sprint Goal only giving purpose to Sprint 0, Sprint Goals being not valuable, or a Sprint Goal ensuring that all of the Product Backlog items selected for the Sprint are implemented, are not valid reasons why the Developers need a Sprint Goal. They may reflect a misunderstanding of what a Sprint Goal is or how Scrum works.
References:
* [Scrum Guide], page 15, section "Sprint Goal"
* [Scrum Guide], page 7, section "Developers"
* [Scrum Guide], page 10, section "Definition of Done"
* [Scrum Guide], page 10, section "Increment"