The selection and editing process for journal articles is complex, and dependant on a number of different people with diverse roles to play. It should be a reliable and formative process, because it involves interactions with a number of experienced people.
The word 'edit' itself has several layers of meaning and 'editor' can mean a number of different things. We tell our students to edit their assignments or essays carefully. Maybe our postgraduate students need some extra help editing their theses. There are editors of newspapers and magazines, editors of books and editors of educational materials, departmental and corporate brochures and newsletters. I am not sure exactly what some of these people do, but I don't think their jobs are quite the same as mine.