After the execution of the Pirate King, Gol D. Roger, the One Piece world saw a new age of pirates usher, and countless people set out to the seas in search of the grand treasure known as the "One Piece." Among a plethora of pirates, there are some, such as the likes of the Yonko and the Shichibukai, who managed to reach great heights.
At the same time, some pirates are quite simply not good enough to be worthy of being called a captain. They either lack any sort of care for their crew or lack the conviction that it takes to reach the summit of piracy, making them unfit for the massive job of leading a crew.
10 Alvida
Alvida was the very first pirate that Luffy encountered on his journey as a pirate. Known to be quite a menace in the East Blue, Alvida led the Alvida Pirates and was known to rule with an iron fist.
She wasn't particularly powerful and the only people who she could scare with her demeanor were the likes of Koby. She wasn't afraid to hurt her own men over something as simple as her insecurities over her beauty.
9 Kuro
Captain Kuro was introduced in the Syrup Village arc of One Piece as a mastermind villain. Known to be one of the smartest people in the entire East Blue, Kuro was shrewd enough to fake his death to get out of the Navy's sight.
He crafted a 3-year plan to attain the wealth of a girl named Kaya, however, thanks to Luffy, he was stopped in his tracks. Kuro eventually planned to kill every single member of his crew, which just goes to show that he never deserved to be a captain in the first place.
8 Don Krieg
Known to be the strongest man in the East Blue, Don Krieg was quite a powerful enemy for Luffy to take on and gave him a lot of trouble during the Baratie arc. Krieg took his men to the Grand Line and returned beaten up after he ran into Dracule Mihawk, one of the Seven Warlords of the Sea.
He later set his sights on Baratie to go back to the Grand Line, however, when his men didn't like the idea, he showed no hesitation in killing them. Krieg even went as far as poisoning his own right-hand man, which is disgraceful, to say the least.
7 Scratchmen Apoo
One of the Worst Generation pirates, Apoo is the leader of the On Air Pirates. He made his debut in One Piece's Sabaody Archipelago arc along with the other Supernovae. While Apoo seemed to be a decent pirate once, with time, he showed his true colors.
He never followed the code of pirates and backstabbed everyone he ever joined hands with. He submitted to Kaido and brought misery to all his other allies. His crew appears to have disappeared and he barely shows any care for them.
6 Basil Hawkins
Another member of the Worst Generation, Basil Hawkins leads the Hawkins Pirates and hails from the North Blue. He's quite a capable pirate and has acquired a bounty of 320 million berries over the years.
Just like Apoo, however, Hawkins doesn't seem to care much about his crew. In fact, ever since he submitted to Kaido, his crew remains to be seen and he hasn't tried looking for them once, which is unbefitting of a captain.
5 Caribou
Caribou is a pirate from the new generation and was a rookie on Sabaody Archipelago when Luffy showed up after the two-year timeskip. Although there's no denying that Caribou lives life like a pirate usually does, he also doesn't care about anyone but himself. All his men are disposable to him and as long as he lives, he's okay. Caribou continues to play a role in the Wano Country arc, and it remains to be seen whether he manages to redeem himself or not.
4 Hody Jones
Hody Jones led the New Fishman Pirates on Fishman Island and put the entire island under his terror regime. His hate for humans was incredibly powerful and unlike Arlong, he didn't care about his own kind either.
Anyone who opposed him, be it a friend or foe, was worthy of death in his eyes, and for such a man to hold a position as great as a Captain is disastrous. Thankfully, Luffy dealt with him quite easily and liberated Fishman Island in the process.
3 Wapol
Originally the King of Drum Island, Wapol abandoned his country and became a pirate when Blackbeard showed up and started destroying the country. His time as a pirate was just as bad as when he was a King. Wapol cared about nobody other than himself.
His crew existed solely to keep him alive and even the doctors that he had on board lived just to treat him. It wouldn't be a stretch to say that he was drunk on power and for him to be a pirate captain is just disrespecting the position.
2 Foxy
Also known as the Silver Fox, Foxy is a pirate captain and the leader of the Foxy Pirates. He's quite an interesting character who made an appearance during the Long Ring Long Island arc of the story, where he took part in a Davy Back Fight against the Straw Hat Pirates.
Foxy tries to engage in constant such fights and steals all the good members of those he fights by cheating. Consequently, his crew holds no respect for him, meaning no matter how many powerful subordinates he gets, he isn't worthy of leading them anyway.
1 Bluejam
Bluejam was a pirate in the East Blue and was introduced in Luffy's flashback after the Marineford arc. He's was quite a despicable pirate and didn't mind murdering his own crew for failure. He didn't think twice before manipulating kids and had full intentions of killing them as well.
When offered the position of a Noble, he agrees to burn down the entirety of Gray Terminal. Even in the world of pirates, there is a moral code and Bluejam's entire being goes against it. He certainly isn't fit to become a pirate captain.