A lot of times, a person develops an addiction, but thinks that they can will their way out of it. While this is a possibility (especially when the addicted person’s self image is as a person who can change their ways easily enough), the power of will alone is so rarely enough to escape from the gravity like effect of a deeply ingrained habit. And if this habit has reached the level of an outright “addiction,” the chances of backsliding into it are extremely high. And even the best of us can fall prey to this siren’s song of the fun and the familiar.
When you backslide, you pretty much do exactly what the term implies. You slide backward, from the top of a hill you just conquered (like giving up drinking) into a valley where you used to be (as in, by falling off of the wagon again). And while it is not the end of the world to backslide on very rare occasions, it is not the path to recovery and sanity that an addicted person really needs. While you could choose to do some kind of activity that you know hurts you on an occasional basis, the risk of going right back into old habits (and suffering through all of the damage that doing such a thing could put you through) more than outweighs the potential for good that such a situation might present you with.
For example, if you were to backslide into being a murderer, you would be risking prison time. No matter how annoying people might become, it is simply not right to go around killing them. And these laws are in place, not to be a “square” or to rain on your parade, but because our world can not afford to backslide into chaos and madness.