I would like to know what does the sentence mean.

I would like to know what does the sentence mean.

" Every great historical change has been based upon nonconformity, has been bought either with the blood or with the reputation of nonconformists "

I want to cite this sentence is relate to my essay about Riefenstahl who made the film "Triumph of the Will". I am on the side that even though the film is well made, I refuse to call great film.