The option isn't taken away. They can go to the grocery store if they want. That's still an option. There's no cognitive dissonance. As an institution, a university is not required to provide every option to its students. It, similarly, shouldn't bar students from making choices they want to make.

EDIT: And if they make choices that turn them into unsuitable students (poor grades, arrests, whatever), the institution is free to suspend them as appropriate.