There was an article that explored this question many years ago, and IIRC, the answer was because the surgeons were in a hurry and didn’t have much time. This problem isn’t as common today with the ubiquity of hand sanitizer dispensers.
Also, try washing and desinfecting your hands 20 times a day. Your skin will start causing problems after a few days, usually dryness, itching, rashes, blisters. Cream helps a bit, but not always. Medical personnel invariably do have skin problems on hands and forearms.
