Who knows why Universal would re-edit DRACULA into an incoherent mess just prior to release. But it's indisputable that they did the same thing to MURDERS IN THE RUE MORGUE, as brilliantly demonstrated by the reconstruction proposed by Tim Lucas and Gary Prange. Studio tampering with movies in the editing process has become legendary, and was occurring long before THE MAGNIFICENT AMBERSONS.

It probably happened for the same reasons that bosses continue to mess up and dilute their employee's output. They have the power and believe that they know better. How much "value added" by meddling managers actually improves the product?