Workers on sailing ships in general were quite susceptible to injuries that would result in loss of limbs. Fingers or limbs caught in ropes, struck by heavy anchor cables or the massive wooden tiller, etc. A cannonball striking a wooden ship would send large splinters of wood flying across the ship, with great damage to eyes. And the only medical treatment offered by of most ‘ships surgeons’ was amputation.
Also, the general state of hygene (lack of water for washing, constantly damp clothes, shoes, hammocks) tended to result in a lot of infections in minor cuts & wounds, and ulcers/bed sores. With the lack of an effective treatment for such, they often progressed to serious enough cases that the surgeon was called in to operate (‘amputate’). And stupid regulations led to sailors postponing any treatment for minor injuries until they became serious (and often too late to be effectively treated). For example, regulations that sailors on sick call were reduced in pay, and (most important) were denied the daily grog/rum ration given to sailors.
So sailors in general had more missing legs, hands, & fingers than other people. And on pirate ships, the state of medical care was probably even worse than on other shops. (What legitimate doctor would choose to set up practice on a pirate ship?) Thus pirates were even more likely than sailors in general to have hooks, peglegs, & missing eyes.