Blackbeard may not have performed as well as Black Bart, but he had the image. Unless Black Bart had burning fuses braided into his beard whenever he boarded a ship...
Unlike Blackbeard, who went out of his way to portray himself to the world as the Devil made man and lived mostly on that fabricated reputation, Black Bart was more of a fop.
It was Black Bart's preference to dress in the finest clothes. By all accounts his manner of dress consisted of scarlet breeches, waist sash and overcoat. He wore a tricorn with a red feather in its band on his head and around his neck hung a diamond encrusted cross on a gold chain that was claimed to have been made for the King of Portugal. His brace of pistols dangled from his shoulder on a silk sash of scarlet.
He had no trouble standing out in the crowd and unlike Blackbeard, who intimidated men into submission with his appearance, Black Bart made men fear his name through his actions not hype (though that as well, in time, did contribute to his success).
He may not have had the same image of Blackbeard but he nevertheless did have an image that made him stand out from everyone else.
As I said before in this thread the only reason that Blackbeard has the notoriety he does is because of Hollywood's preference for him. While Blackbeard was made the superstar of the pirate world by the powerful America entertainment industry other more successful and accomplished pirates like Black Bart and Henry Morgan were ignored, in fact Black Bart is often confused for some late 1800's highwayman in California.
Again the point was that Blackbeard had the image and the hype to be a great pirate but little else while Black Bart had the image, the hype and all the talent to be a great pirate and he was.
It is telling that the man who commanded the ship that brought an end to Black Bart short but terrifying career was the only man ever knighted for killing one pirate while the man who commanded the ship that brought an end to Blackbeard career was not even recognized for his feat on the European side of the Atlantic, in fact he was barely recognized for it outside of the Carolina's and Virginia.