The latest issue of Vanity Fair has an "oral history" of The Simpsons--interviews with various people who have been involved with the show over the years--and the end result is pretty amusing. This part was particularly hilarious, or depressing, or both:
Jay Krogen: We thought we were really writing these really funny, smart, special shows that were chock-full of jokes every few seconds. And then someone showed us this study Fox had done: the No. 1 reason why people liked The Simpsons was "all the pretty colors" and they liked it when Homer hit his head. We were writing the show for ourselves--we always made it funny for ourselves--but who knows why America likes it. Maybe they like the pretty colors and when Homer hits his head, but I hope it's for more.
It's also fun to note that, back in 1992, George H. W. Bush was railing against the show as evidence of America's moral turpitude and the general decline of family values. These days, though, you can't pick up an issue of the National Review without seeing Simpsons references all over the place. A few years ago, Deroy Murdock even heaped praise on the show for depicting "a tightly knit community of generally endearing neighbors who, somehow, all get along." It's been quite the turnaround.