I agree with you. I agree with you so much, I made a cartoon rant about that exact issue about 13 years ago. It deconstructs the show and explains how it went from social satire to a toothless celebration of popular culture after the first couple of seasons. Now that I've finally met you, let's get married.
Every so often, a friend will get me to watch an episode with him. 30 minutes later, they've chuckled maybe once during the entire show, and then tell me "oh, it wasn't one of the better ones."
I'm pretty sure Conan O'Brien ruined the show. He's the one that started with the totally-unfunny non-sequitorial pop-culture references, and everyone followed suit. If the show had always been mediocre, I wouldn't care. But for once in television's shoddy history, something genuinely intelligent and subversive was piercing through the sheen, making people think and laugh at the same time, and then... poof. Thanks, Conan.
Hey, Rob, the Simpsons did die! 20 years ago!