I was going to post that. I read all the books as a child, and actually, the first one is, IMHO, the weakest of the original 14 written by Baum himself (a granddaughter, or niece, or something, wrote a bunch more, but I never liked them). Not that it was bad-- just that, if I had to rank them, it would be last.
Dorothy never wanted to get back to Kansas, she wanted to get back to Aunt Em and Uncle Henry, because they needed her, and that is made quite clear in the beginning of the book, before the cyclone. She is their reason for plugging on, and the only brightness in their lives. This is not the case in the movie, where she seems to be in the way, and inadvertently cause them a lot of trouble, which I think is a mistake.
But actually, the whole “There’s no place like home” moral is a mistake. Baum says in the preface to the first book that he wanted to write a book for children that was not didactic, not an Aesop fable, but just plain fun. The movie ruined that, IMHO.
After her second trip to Oz, when Princess Ozma is in charge, Dorothy and Ozma figure out a way for Dorothy to signal when she’d like to visit Oz again, and she returns home, but future trips are in the offing. Then she convinces Aunt Em and Uncle Henry to move there, and they all take up permanent residency.
Oh, and my 13-year-old has always loved it-- well, the first time he saw it, the witch scared him, but he got over that, and now he loves the whole thing.