Great Movie, Practically Perfect, Why Was It Ever Remade?

In keeping with this month's quest of watching movies which are more or less Halloween themed but not too gruesome or depressing, I chose The Witches from 1990, which is said to be the better of the two film versions. This film was so true to Roald Dahl's book it was almost an exact copy. It was well cast and well acted with good special effects. Anjelica Huston was perfect as the Grand High Witch. Rowan Atkinson was even in this movie and he was great. The only major difference from the book was the ending. The book ending wasn't a total downer but it was very somber. I guess the lesson was supposed to be that life isn't fair and not everyone can have a happy ending but should try to do the best with what life hands them. This might have been an appropriate ending for the book (although it didn't sit entirely right with me) but not for the movie, which does deliver a happy ending. I can hardly believe this film was remade. I believe films which got it perfect the first time should not be remade. I'm not going to add this to the "Movies Better Than the Book" list but it is as equal to the book as a movie can get and I liked the ending better. Unfortunately, for reasons I fail to fathom, Roald Dahl hated this movie and it seems to be only partly because of the changed ending.