In a wide range of professions, decisions are required and conclusions must be reached about alternative courses of action. Data must be collected to throw light on these problems. Statistics is a body of techniques that provides useful information to decision-makers from such data.
Although there is much to be said for teaching statistics within the context of an application area that is relevant to the career of the person learning the subject, statistical data analysis is based on the same approach and basic 'toolbox' of techniques in all subject areas.
By teaching statistics as a separate discipline, we emphasise this common approach to using data to obtain information about real-life problems.