> However, I suspect its secret is that it's really a show for parents with young children that just happens to hold the attention of kids.
That's how a lot of successful children's movies/shows work in a way.
Have you ever rewatched older kids movies as an adult and realized how many adult-level jokes they slipped in that you never noticed as a child?
If you're asking parents to spend 1.5 hours at a movie theater, you better throw in some adult humor in there as well.