>>213490088
Pirates raid and pillage EIC ships or towns and ports in the British Empire. This hurts the pocket and reputation of the EIC, which had its own personal army and navy. Beckett wanted the seas to be safe for him to trade his spices, slaves, fancy bananas, anything you can think of, to elevate his career to british nobility. There was no better way to do this than killing off all pirates, putting the fear of the devil (Jones) into potential pirates and having an immortal sea monster and his crew protecting his interests.
For Beckett it was just business. Turn enemies into employees or kill them off. He wanted Jack to be a privateer and presumably has more. The entire message is that piracy is dying due to the changing scenery of the world. There was no more places to discover, all the magic and mystique was filled in with the map. Places a pirate could call home were dens of law and order now.