That was the committee at the time of writing. If anyone refers to this in, say, a year, they will have no idea who was responsible. As an analogy, transaction histories, if done in a DB, are not normalized because you wouldn't want the price and total sale of a past transaction to change when you later change the price of the items that were in that transaction. Sometimes, it's actually good to duplicate code/data/effort, especially if it helps to make something clear.