Yes it asks about quality, but if faculty are friendly and funny, students will score you high. If you are quality but not friendly, students will score you low. It's a popularity contest for college faculty, not exactly a great way to make a decision about your college choice.
If a student doesn't get what they want, even if they get what they need, they will score low. For example: the institution I am currently working with is scored pretty low. They're a science and technology focused institution with a niche related to electrical and mechanical engineering. The first year is general education, then you get into your specific major.
The scores are low, because the schools inside the university are VERY selective. There are a large number of freshmen who do not get into their first choice major their sophomore year. This is because they don't have the necessary achievement to be competitive, not because the school sucks.
But, if you look at the rating on rate my professor, the school looks like it's full of sociopaths bent on destroying children's futures.