Everyone is parroting the same thing over and over again, but no one is going into the whys. Why do this, what's the benefit, how will it thwart this or that ty

Everyone is parroting the same thing over and over again, but no one is going into the whys. Why do this, what's the benefit, how will it thwart this or that type of attack. New books on the subject tend to collect these guides, distill them a bit, and parrot it all over again.