There are several different factors wrapped up in each “grade.”
For example my child’s school, UC Berkeley, received an overall “D” (link) apparently due to many hostile incidents and student groups on campus, but also received many positive marks for “Publicly Disclosed Administrative Actions and Policies” and “Jewish Student Life on Campus” (which is indeed strong; we have a wonderful Hillel that, as far as I can tell, has been doing a great job of both supporting students, and making space for the range of Jewish student perspectives in this school community).
Looking at this details page would give parents and students a better sense of what they might expect at each university, rather than just the “grade.”
Students and their parents should consider what factors are important to them.