I just watched the making of THE AFRICAN QUEEN and apparently John Huston didn't expect such a charming and funny tone until after he started filming and witnessed the chemistry between the two leads. He was going to kill Charlie and Rosie off at the end (or for sure at least have them fail) and then after much deliberation/collaboration, decided they write a new more upbeat ending. Now, I understand this isn't THE AFRICAN QUEEN and this isn't John Huston, but...
Nevermind. Tim Burton's got one tone. QUIRKY & CREEPY (QUIRKREEPY?)
To expect anything else is pure folly.