I was a center and played some college ball. Centers don't wear cups. It causes fumbles and can do more damage to thyself if the QBs hands are in just the right spot.
In fact, there is a lot more intimacies to that exchange between the center and the QB than most have ever thought about, especially as the game gets faster at higher levels. Hand position and the first .25 seconds after HUT can go anywhere from a jewel crushing pain to fumble depending on exactly where the fingertips are when the ball slams into position.
Trust me. It gets taken for granted at the college and professional level. You centers out there will no what I am talking about.
centers will KNOW what I am talking about......what college was that???