To address the failing quality:
The Simpsons once mocked and then it became mainstream pop culture. So that is a cause of why it has declined.
And another cause is that there is a new PC comedy trend to laugh at things. As in the audience is expected to laugh at the object itself without having an actual joke behind it. As in, "This is a computer, Laugh at it!"
Because of that we see a transformation of the jokes. The celebrity guests were once the butt of the joke. Mulder and Scully came on and the Simpsons mocked them. Now the joke is the celebrity guest. As in, "This is Lady Gaga," or "this is Michelle Obama."
They aren't spoofed or satirized in any way, the audience is just asked to laugh at the fact that they have a celebrity guest.
And the final reason is the laugh track comedy, in which the Simpsons has none. That is no laugh track. But now the writing sets up the jokes with almost a pause for laughter as if the tracks were there.
In the past the jokes were piled onto one another. There would be several jokes stacked right next to one another in a single event. Now it has become joke, pause to acknowledge the joke, continue.
But no ones really laughing because it's no longer mocking culture, it's no longer spoofing the celebrity guests, and it's lost virtually all of its edge.
Created by
Matt Groening
Top cast
Dan Castellaneta·Julie Kavner·Nancy Cartwright·Yeardley Smith·Hank Azaria·Harry Shearer·Pamela Hayden·Tress MacNeille