It's really crazy to think that multiple generations have enjoyed The Simpsons over the past 26 years. I was born in 1990 and the show started in 1989, so the show has enjoyed a longer lifespan than I have!
I think a lot of its biggest fans can say the same, but some of its older fans fell in love with it as well and haven't yet let go. The show taps into the zeitgeist and still lures in older folks and teens alike.
I think shows like Family Guy, South Park, [American Dad!](tag:721012), Futurama (which was created by the same people as The Simpsons), etc. all have creator Matt Groening's unique and creative mind to thank for their inspiration.
Sadly, the show's current showrunner, Al Jean, had this to say about the possible end of the series (which would be incredibly emotional) to The Hollywood Reporter:
“It’s quite possible that we don’t have to go through the whole negotiation for 30. I wouldn’t be stunned if we stopped at 28, but my bet is on at least 30. But then you’d have to resign them again. If you made me pick one, I’d say the likeliest is ending after 30, but I’ve been wrong before. I thought five seasons was good when I got there.”
We'll see... it truly does seem like "They'll never stop the Simpsons."