To be fair, the simple kanban doesn't stop you from creating a scope/goal, you need to generate your TODO list somewhere, which isn't any different from sprints, but it's less rigid when it comes to the deadlines.

More to the point is, setting sprint goals is defacto pressure which many people and orginsations are poor at handling, and we can largely avoid it by not having people doing or managing the work care about end of sprints, but just that the tasks are scoped and are of a reasonble size.