UCL Course Satisfaction Low?

Taking Neuroscience BSc, for example, Discover Uni says only 59% of the students are satisfied with the course (see link to screenshot below):
https://imgbox.com/VG67kSQg

Why is that the case? UCL has very highly ranked neuroscience courses, so I have to assume that satisfaction percentage isn't super reflective of the quality of the course. But if that number is useless, then it shouldn't be on there in the first place.