I'm not sure what conscience has to do with entertainment. Entertainment needs to be distracting, in that it distracts from the vicissitudes of everyday life. But your focus moves to the entertainment, if it is good entertainment, and it distracts you from what you normally are focusing on. But you are focusing on the entertainment at that point, rather than on something else. So it is a voluntary act of will. It is dangerous to focus on one thing when your attention should be elsewhere, but it is the responsibility of the entity, not the medium itself.