Until I read The Scrum Guide I had never heard of having a Sprint Goal. My company tries to follow Scrum but they don't use Sprint Goals either.
I very much agree with the idea of having one, but I don't understand how that doesn't clash with the ideal of being able to take items from the top of the Product Backlog each sprint and shifting them straight into the Sprint Backlog.
In other words, what happens when prioritisation and Sprint Goal don't agree? One of these two things has to give; isn't something going to get shoehorned?
Similar clashes of concept: