Is it beneficial for a university to allow citizens to audit classes with undergraduates without receiving grades or earning credits?

Feedback and grades are crucial incentives in the learning process, and I don't think it's a good idea to offer free courses to community members but not give feedback and grades. For one thing, interested community members need the motivation to stick with the class. Teacher comments and grades represent progress and affirmation for students, and without these formal elements of the course, community members may not stick with it.

Secondly, a course without feedback may confuse the participants because the instructor's feedback also marks the progress of the course. Community members are busy, and they may not remember the progress and effectiveness of the course learning. And with the instructor's course feedback, they can better complete their assignments and arrange their schedule, thus improving their learning efficiency.