Views can be used for many different processes. One of these is for security purposes. Within the view you can limit exposure of data and provide only necessary columns to the user. This is where you allow exporting through view the data. Another purpose of a view is you can handle the relationship within a view for many tables and then provide the final output for exporting. For example, you have a student table, a grade table, and set up a view of student grades. You could set up access to only allow certain rows (say for a particular teacher) using that view. When the teacher request the data through the view, the teacher would only get his students and their grades. This is a basic example, but it show why you would want to export data within a view.
Hope this helps.