As an educator, I do not consider it my obligation to provide employers with effective evaluations. I am an educator, not an interviewer. You want effective evaluations, pay for them.
I think grades are very much an indication of performance, more generally a valuable part of the student experience and growing as an adult, if you can't be bothered grading...step aside, plenty of other people want your job and are willing to work for it.
Outside of a handful of “elite” schools, I literally could not tell you anything about the quality of most schools.
I care far more that you can actually deliver value.