AV Club posted:

That, in the end, is the true betrayal of “The Principal And The Pauper.” It’s not that it’s a terrible episode of The Simpsons, or that it forces you to have this element of the character in your mind every time another Principal Skinner storyline comes up. No, what damns this episode in the history of The Simpsons is that it’s where it became clear for the first time that the people making the show didn’t hold Springfield and its citizens in the same light as so many of its fans. The message sent was that preserving its carefully constructed universe was secondary to the goal of producing an episode, and this world could be taken apart and put it back together as necessary. And the act of disassembly and reassembly, performed with ever more frequency from season nine on, is what spelled the end of The Simpsons Golden Age.