The Simpsons writers lost sight of humor about 23 years ago, and they've been slogging along like a dumb lazy overpaid zombie since then. The think they're making fun of pop culture but that was the 90's In the new millennium they just go along with pop culture to get ad revenue. It stopped being about entertainment back in season 9 or 10. The same year they sent some of their best writers to work on Futurama, which is a much better show.
You can go to youtube and watch a video called "The Fall of The Simpsons: How it Happened". Its 31 minutes and 8 seconds long. Very good description about how everything went to hell.
THIS ONE attempts to spoof modern American cultural obsession with young female pop singers, which is at least 20 years late. Instead its basically just kissing their bottoms, which is very much contemporary. And not one joke in the whole 21 minutes was funny. They got somebody I guess they think is famous to boost ratings. Its terrible. I wish they'd have killed it off in 1999.
Go watch. If you like it, you are part of the problem. If you dont like it, please do not watch this show, at least not on primetime. Let the ratings die, let the series die, let us all move on to the future.