First of all that is because students are not consumers. They are supposed to be co-producers. The idea that students are consumers harms the students most profoundly. No one who does not take responsibility for their own education can learn. In addition the model of students as narrow consumers is part of the ideology that has led to the massive dis-investment in education, and the corresponding creation of debt. If you intend to reify that on wikipedia, at least do not do it in a vacuum of ignorance. Second, and speaking of vacuums of ignorance, it is a bad idea because of the very well- documented biases against women and men of color in evaluations. I am assuming that the person suggesting this is SomeDude whose life experience is being a white guy in CS. Perhaps googling gender bias would help. In general, wikipedia has not been a particularly hostile place to women. Of course, adding this would open that to change for female academics. Third, rate my professor obviously already exists. In addition universities offer internal ratings in which the ratings are provided, by people WHO HAVE ACTUALLY TAKEN A COURSE. Fourth, teachers and instructors who teach in contested areas would be downrated by ideologues, e.g. I am sure gender studies will become a pastime for MRAs. It is a deeply political choice that will have little valid output, provide a platform for ideological culture war venom, further reify the idea that an education is something that is passively consumed, and create a duplicate platform where there already exists superior ones. I will endeavor to think of one good thing, and if I do I assure you I will return to post it.