I simply proposed it as an augmentation to assist in protection when used in conjunction with another method. The answer supports my argument that the woman can't depend simply on relying on the absolute cyclic nature of her ovulations. There are many ways a woman could determine her cycle. In fact, there are many ways that a woman could know when she has begun to ovulate. I've already explained how these neat and tidy solutions don't work for all women.
Few women are as regular as clockwork when it comes to their monthly cycles.
Women do not always ovulate on the same day every month and do not always exhibit the same physical reactions to the onset of ovulation. This will throw your advocated ovulation pattern completely out the window. The bottom line is that each woman is different and you can't apply blanket and stereotypical solutions to all of them as a group. You are always going to have to consider the circumstances of each individual case. This is what strictly moralistic solutions are so poor at doing.