Tough math teachers get lower ratings from students, because students like them less. However, students get better grades with the tough teachers than with laxer teachers. Reason #167 why student evaluations of teaching aren’t particularly useful.
https://www.stevestewartwilliams.com/p/implicit-bias-training-the-psychology
This is why, for all its faults, I do support standardized testing. Without standardized testing, every incentive is for teachers to go easy on the students. Easier for the teacher, easier for the students, bad for learning.
Lol, only tough (brutal) teachers get good ratings with an unconditional support from parents.