Bruno Bucciarati is a supporting protagonist of JoJo's Bizarre Adventure part 5 (Golden Wind) and perhaps one of the strongest Stand users of the group. His "Zipper Man" allows him to unzip any surface, including metal, concrete, and even human flesh.
Like any complex character, there are a number of flaws and shortcomings amidst his active career in the anime which work both in his favor and against it. By analyzing his history, battles, and facets of his personality, we can determine whether or not he was worthy of being the leader to his team.
9 Good - Getting Mista Out Of Prison
Before meeting Bruno, Mista was destined to rot in prison for his participation in gang violence. After Bucciarati heard of the valor he displayed, he knew that such talents would be put to waste if the verdict remained - and that his prospective friend would not survive his stay in jail.
Hence, he would use his mafia connections in order to change the outcome and offered Guido the chance to join his team. Indebted and with no better prospects, he would agree and become one of its most loyal and resilient members.
8 Bad - The Taste Test
When investigating the death of Luca, Bruno was eventually able to corner Giorno. Instead of applying a rigorous line of inquiry or attempting to gauge his psychological profile, he licked his face, claiming that by doing so, he could taste if his subject was lying.
While this is disturbing in of itself, the most egregious aspect of this "solution" is for the fact that it was the only time he would use this ability throughout the duration of the series. It would have come in handy against such opponents like Mario, where information was vital and time was of the essence.
7 Good - Defended Trish From Diavolo
The initial mission for Bucciarati's team was to escort the Boss's daughter, Trish, into his safekeeping. When they had finally reached the drop point, Bruno was chosen to go alone and deliver her into his waiting hands.
In the bunker, he would discover that Diavolo had sought to kill his own child in order to keep his identity obscured. Horrified and appalled by this, Bucciarati and his new friend fled the man - though the former did not manage to escape unscathed.
6 Bad - Lying About His Undeath
While Bruno had technically "died" in his first encounter against Diavolo, his corporeal body and lingering spirit were able to assist the group even after his passing - though they had no idea of his demise to begin with. Bucciarati adamantly attempted to keep it a secret from them, even if Giorno would have his suspicions.
As the leader of the team, the man had a responsibility to tell his allies the truth, especially since they had betrayed the boss and risked their own lives in order to follow him. His decision to keep it a secret was a profane misuse of their trust.
5 Good - Defeating Pesci
After his older brother had been defeated, Pesci and Bruno were the only people of their respective teams still in fighting condition. With the train stopped, they had their final confrontation outside of it - one which would decide the lives of Bucciarati's comrades.
Despite the power of Pesci's Stand, Bruno was able to outmaneuver him, unzipping his body and dicing it into dozens of tiny pieces. It would save his ailing friends and allow them to continue the mission they had presumed themselves to be on the cusp of completing
4 Bad - Abbacchio's Death
When the team had finally gotten to the beach, Abbacchio had begun to use his Moody Blues Stand in order to rewind the events of the location that Diavolo had once stood. Ideally, this would uncover the criminal's identity and give them a target to attack.
Despite the recurring threats the team had faced, Bucciarati did not bother to have someone defend Abbacchio during this time. Instead, he and Narancia decided to comb the beach and look for enemies, rather than stay put and defend their friend. This would be perhaps the greatest lapse in judgment of Bruno's career.
3 Good - Defeating Mario
Mario had managed to infiltrate the yacht and was one of the first antagonists Bruno fought against alongside his group. He was also among the most successful; his "Soft Machine" Stand took out virtually everyone in the party, including Giorno.
However, Bruno was able to uncover the secret behind his Stand's power - specifically, that he could pull one physical object over another, effectively "rubberizing" them. This allowed him to sniff out his opponent and strike him down, making him the perfect candidate for questioning.
2 Bad - Attacking Giorno
After Giorno had failed his "taste test," Bucciarati decided to attack him. This emphasized the fact that despite the admirable qualities Bruno would display in the fullness of time, he began his journey as a minion of the Boss and was ultimately a career criminal.
Should Giovanna have failed in this fateful encounter, it's likely that Bruno either would have killed him (as he had done against many of his enemies), or escorted the son of DIO to someone that would. Giorno was only able to sway his heart with a show of force.
Secco was the former test subject and unlikely pet to the insane and sadistic Cioccolata. When the duo would be set upon the group, Bucciarati would face him in single combat (unlike Giorno, whose efforts against his master were reinforced by Mista).
Despite Bruno's withering undead body, he managed to defeat the tunneling Stand user after a hard battle, depositing him into a trash compactor alongside his master. It would be a profound display of Bucciarati's competence and ability to excel in spite of his dire circumstances.
1 Bad - Losing Trish
As adamantly as Bucciarati fashioned himself a defender of Trish and the innocent, he had failed in his duties more than once. When Melone's "Baby Face" Stand had infiltrated the turtle and stolen her, Bruno's defeat was almost as instantaneous as her own, as he was diced up just as easily.
Ultimately, Giorno would be forced to defeat the Stand in his stead using the newfound powers of his "Golden Wind" in order to do so. It was a massive failure on Bruno's end and one that could have cost the team everything they had purported to protect.