Because education is a right and everyone has the right to an education. In my own opinion, it is also a civic duty. The concept of a civic duty is that it is a responsibility expected from all members of a society. Following the principle that citizens have an obligation to serve their society. In return, they receive certain rights and protections.
E.g Learning in the Phillipine Science High School gives you the right to a DOST scholarship, requiring you to take a STEM course and to work in the Philippines for a set amount of time. Refusing such responsibility requires you to pay back all that you've got from the school.
