I hate how in Disney family sitcoms as well as some cartoons, there's always the stock dumb kid that gives the majority of the humor, and it's humor that gets old.
The example I think that got me to dislike the trope was in Austin and Ally. The character Desmond was eating a muffin with the muffin wrapper on, and one of the characters mentioned you "have to remove the wrapper before eating it", so he removes the wrapper and throws the muffin away and starts eating the wrapper because that's how he interpreted their advice. And I'm thinking has there ever been a teenager who didn't have some instinct on how to eat a muffin.