In the comics, the accident that causes Victor Stone to be transformed into Cyborg is also one that took his mother's life. So on top of Cyborg resenting his father Silas for taking his humanity away, their relationship is further fractured by the anger and guilt associated with Elinore's death. This backstory would help explain the sense of loneliness and bitterness that Cyborg was feeling in Justice League, and why he might have refused to join the team when first recruited by Diana Prince.