I always feel the weird one out in these discussions because I was a kid that disliked art styles in shows or knew the writing was bad, and that some things were dumb down when it shouldn't have been. And I'm sure many people felt the same, especially during the 2005-2010 era when shows were starting to get very bad and people thought they were just losing interest in cartoons because they were getting older, but really it was just the shows thinking that anyone would watch what they produced.
Look at the most successful cartoons, they entice both kids and adults. They are well written even if some have butt and fart jokes, they are well animated, sometimes have great scores, and can either be episodic or have long stretching plotlines. There is a mix of everything, some people have preferences because there were great shows from their childhood and it hurts seeing a bad rendition of it. (Powerpuff Girls is a great example).
A temp-stand in Professor at my college made a great point:
"When a new entry or reboot is made and it's outright terrible, people like clamoring that it's ruining the entirety of everything because what you enjoyed then was good, splendid, and memorable. But one bad reboot doesn't ruin everything, you're going to look back and say 'Yeah that one sucked' but you are still left with a lot of good things from the original to enjoy, and maybe down the line, a reboot or sequel improves upon the original, or maybe it will fail again. But you will always have the good times the original content provided and nothing ruins that".