No shit basing compensation on reviews by people who have an overt bias to blame the instructor.

The purpose of the review should be purely to provide feedback to the instructor and TA. It should not be available to the administration - the purpose is to help the TA and instructors improve their teaching. Especially if the instructors have tenure and so can’t be fired for failing to teach.

Ratings should also be scaled to control for biases - what are the average grades given by each student, how do they compare to other students in their classes, and to their course grade.