Here's the take-away quotation for me: The better the professors were, as measured by their students' grades in later classes, the lower their ratings from students. "If you make your students do well in their academic career, you get worse evaluations from your students," Pellizzari said. Students, by and large, don't enjoy learning from a taskmaster, even if it does them some good.
The methodology is flawed. If a lecturer really is terrible, then more people will fail that course and not go on to do the advanced course, artificially raising the average for the advanced course because only the best students are able to pass the prerequisite DESPITE the terrible lecturer.
Like one guy I didn't learn a thing from, because he constantly mumbled and wrote in really tiny print on the whiteboard... yet the class before each test, he'd discuss every single test question in detail and tell us the answers.
A friend of mine had him for something else, and at one point after delivering a graded test, he said "if you didn't like your grade, give your test back to me and I'll give you more points". My friend, who got a 95, decided to give it back out of sheer curiosity and got back a 98.
Edit: Hey, I have another story about this dude: another friend of mine had him for a class. This friend is legally blind, so he once asked for more time to take the test since it takes him longer to read everything. A perfectly reasonable request: it's even listed on the form of accomodations offered by the university's Disability Services. Well, when the professor filled out the form, he granted my friend literally every single disability accomodation the university offered. He ended up with dozens of accomodations he didn't even ask for