likely because Warner Bros. probably felt people wouldn’t care for something that awesome.
Thankfully a fan did their best to create this black & white cut of Fury Road, without dialog just as George Miller intended the special version to be:
“George Miller has said that the best version of his film is in black and white, with no dialogue. BLACK & CHROME is an attempt to realize Millerâ€™s alternate vision. The cinematography, the editing, the sound design, and the score, are now represented in a completely new experience.”
They uploaded the entire movie to Vimeo, which you can see below. While Vimeo is generally good with fan edits such as this, and they rarely pull them down when a studio complains, you should watch this while you can: