It worked as a popular film, but that does not qualify it for stage adaptation. So much of the film was intimate close ups -- that won't work in a 1600 seat house. The movie does not need to be a stage musical -- nothing screams out demanding it be musicalized. The story lacks strong characters or interesting plot elements; the entire emphasis will be on the dance which cannot be duplicated since so much of it was faked with clever edits and cuts.
Another WHY musical ....