Back to the OP, I would look at 3E's Waterdeep: City of Splendors or even the original Waterdeep and the North. Large portions of Waterdeep's nobility are downright evil. Many more are neutral. Few are good. It's right there in the text, indisputable. Additionally, the Open Lord has limited powers. It's a public position, presumably controls the military against external threats, and directs the city watch. Meanwhile, any noble has the ability to accuse a commoner of a crime and their word is taken as law in the courts. In practice, that means any evil noble can make a false accusation of a capital crime and the city will execute the defendant on the noble's behalf -- with no recourse. Does this not sound like a city in need of a little revolution?