The goal of treating your sexuality sacred is to bring you to a point where you can actually live in a state of harmony and fulfillment with your sex drive. In order to understand this relationship, think about fire. There is a certain level of respect that we have to give fire. This is because it has both tremendous capacity for benefiting us, but also a tremendous capacity for destruction. We respect this capacity by only lighting fire in contained and appropriate settings.
By respecting fire this way, human kind has effectively used fire as a means of survival for centuries. Much in the same way, human kind has relied on the burning passion of sex for its continuation. But just as a fire out of control is a beast of destruction, so is a sex drive out of control. The way I see it, turning to pornography and masturbation whenever you get a sexual urge is the same thing as lighting the nearest curtain on fire whenever you get cold. It is a recipe for destruction.