Kubrick Disowned this Film
It was never his project. Anthony Mann began as director, but had issues with the star Douglas. He had Mann fired, then asked his 'friend', Stanley to take over.
Kubrick had little, if any, artistic control, and was essentially just a hired hand.
Kubrick even mocked SPARTACUS in the opening scene from his next pic, LOLITA. A spaced-out Sellers tells Mason "I'm Spartacus, have you come to free the slaves?'
Kubrick never considered SPARTACUS a Kubrick Film, and never included it in his body of work. Just a paid assignment in between his real projects.
Heard that Stanley and Kirk had constant issues during filming.
This film lacks Kubrick's distinctive visual style.
Also, the romantic sentiments were not 'Kubrick elements' Too cold and cynical a director he was, never coddling to bleeding hearts.
He was one of the films' harshest critics.
I have wondered how it would have been if he had his full artistic control over it, that is if the story even intrigued him enough to want to do his own vision of it.