In fact, damage of various kinds is not all that uncommon, it just often goes unreported. A surprising number of men have a scar across the head, a stray tag of skin hanging off their penis, or ugly lumps where the two kinds of skin healed together and where the veins had to find their own new routes. The pain of circumcision is now known to be excruciating, and can only partly be deadened with drugs. Better not to give babies drugs anyway. The shock of circumcision makes breastfeeding harder to establish.
Worse things can go wrong with circumcision.
You may have heard of the man in Winnipeg, Canada who was raised as a girl after his penis was accidentally burnt off or the boy in Washington state who's brain-damaged. Babies sometimes die from circumcision - very rarely, but that's small consolation to their parents. Cutting off part of boys' genitals goes back to the dawn of time, probably to Africa, but it was invented independently in Polynesia and Australia. It seems to have arisen as some kind of magical attempt at taking control of sex. Maybe it was to make the penis look like an erect one all the time, giving magical potency.