Here's why:
* Freedom of Expression: The First Amendment (in the US) and similar rights in other countries protect the freedom of artistic expression, including the freedom to create stories with any kind of ending.
* No Legal Obligation to Happy Endings: There's no law that requires movies, especially children's movies, to have happy endings.
* Diverse Storytelling: Kids movies, like any other genre, can explore different themes and emotions. Sometimes, a less-than-happy ending can be more meaningful or impactful.
However, it's important to note that:
* Audience Consideration: While a bad ending might be acceptable for older children or teens, it's important to consider the target audience of the movie. A very young child might not understand or appreciate a sad ending.
* Context and Theme: A "bad" ending can be effective if it serves the story's overall theme and message.
In short, there's no legal issue with a kids movie having a bad ending, but it's a matter of artistic choice and consideration for the intended audience.