the government should choose the disciplines that students will study in the university.
what?! When would it ever be appropriate for the government to decide what people study? It is not appropriate for parents or government to make decisions for other people....
Keep the tense the same:
Moreover, students might feel disappointed and discouraged
discouraging if the subjects which are chosen for them are the disciplines they do not want to learn.
On the one hand, the government should recommend some disciplines to students who are indecisive about what they are going to study in the university----Everything you wrote is very wise and eloquently expressed. This is looking good. I cannot imagine anyone ever thinking the government should choose for students.