First of all, students should be given the opportunity to take their future into their own hands. Before students move to high schools, they have studied in primary schools and best know the subjects they are good at. Some even decide the subjects they will do in high schools while they are still in primary schools. So, choosing a subject for students like these ones who have already made first hand decisions on what to do in high schools will be detrimental for them and their career.
Furthermore, some students already know what to do in future before they move to high schools. There are students whose family members are already workers in places like; companies and hospitals. A student might decide to major in electrical engineering because a family member has guaranteed him or her a job in an engineering company. The school might not know this and decide that the student takes arts courses. This will be doing more harm than good to the student, and there is a high possibility that the student will not have the desire to study in that domain, because he/she does not know the importance of it in his/her future.
Finally, some students hate certain subjects in primary school, and will want to avoid those subjects when they move to high schools. While in primary school, students perform differently in different subjects, and will want to avoid those courses they consider as their personal nightmare when they are in high schools. If subjects are to be chosen for students, there will be a possibility that one of these courses might be selected for the student. If he/she continues