Students contributing to open source to get better grades should have a flag on GitHub so project maintainers can easily recognize them and treat their contributions with an extra bit of care. I've been consulted by students (and PhDs) regarding their final project (not strictly IT related) and the song was always the same. The primary objective of that person is to get uni finished. Quality or usefulness of their work is always second place. What counts is the grade they get in the end. I always felt used if not "raped". These days, I turn all students down.