Warning! Spoilers for Dragon Ball Super chapter 77 ahead!
The retcon of Goku's father Bardock in the Dragon Ball Super manga not only makes him a kinder Saiyan than his original portrayal, but a better hero than his son. Bardock is best known for how he saved the life of his infant child, then known as Kakarot, before Lord Frieza destroyed their home world, a tragic story first portrayed in the film Bardock: The Father of Goku and then later reimagined in the movie Dragon Ball Super: Broly.
An old Namekian named Monaito uncovers more about Bardock's life in the manga to stop an ongoing battle between Goku, Vegeta and Granolah, a Cerealian obsessed with avenging the genocide of his people perpetrated by Saiyan mercenaries in the name of Frieza. Before the epic confrontation, Granolah learns that powerful Saiyans known as Goku and Vegeta exist and orchestrates their demise just on the basis of their race, even though neither of them were old enough to participate in his people's murder. All of Goku and Vegeta's attempts to quell the Cerealian's rage fail horribly, but Monaito at least temporarily stops Granolah's rampage in chapter 77 of Dragon Ball Super when he explains how Goku's father Bardock actually saved both of them, a truth Monaito wants Granolah to know before he inadvertently murders the son of his savior.
As Monaito reveals, Bardock risks certain execution in order to save the lives of those he has been tasked to kill - a young Cerealian boy and his mother. The Saiyan first lies to his fellow comrades that he planned on staying behind after the genocide to ensure there were no survivors, when he really uses that time to find someone who can provide them shelter: the Namekian Monaito. Bardock later has to jump through even more hoops for his enemies when Frieza's business partners, the Heeters, suddenly arrive on the planet and become aware of Bardock and his companions. When they confront Bardock, the Saiyan initially tries to talk his way out of killing them but is forced to fight against his former allies after they kill Granolah's mother.
It's remarkable that Bardock risks his life to spare his enemies. Even Bardock believes there has to be something wrong with him. There might well have been because Saiyans are known to be natural-born killers who express no remorse regardless of whom they murder. Even Goku wasn't pure-hearted at the beginning of Dragon Ball. Upon his arrival to Earth, he was a destructive child who relished in chaos and actively endeavored to create as much mayhem as possible. It wasn't until he hit his head that Goku became the kind-hearted and pure character he is now; an outside force literally had to knock the evil out of him first before he could become a hero. Meanwhile, Bardock changes for the better on his own in Dragon Ball Super's interpretation of him. When he first lays eyes on the cowering figures of Granolah and his mother during the Cerealian massacre, he doesn't see two targets he must kill. He sees in them his wife and son Kakarot.
The eponymous Saiyan in Dragon Ball Z's Bardock: The Father of Goku would have never found such redemption. Even though Bardock saves his son from Frieza, the film mostly portrays him as a stereotypical Saiyan who mistreats and actively enjoys killing his victims. In fact, Bardock only turns on Frieza because he gets cursed with the ability of foresight and witnesses the future destruction of Planet Vegeta. When Dragon Ball Super initially retconned his character in the rebooted Broly film, how Bardock interacts with his victims is never shown, allowing him to be interpreted as an individual who could care for his enemies, as the series later shows in chapter 77. The end result is that Bardock doesn't need to get cursed or receive blunt-force trauma to the head like in Goku's case to become a better and more heroic Saiyan. He already naturally possesses what's required: love.