Because doctors are clueless. They are treating a symptom of a symptom. If you are suffering from chronic skin inflammation due to topical steroid addiction, your skin barrier is damaged due to the application of topical steroids. The doctors, with kind intentions, believe that slapping moisturizers will help to seal this moisture barrier. And they prescribe more topical steroids at the same time to manage your inflammation (causing further skin barrier damage). None of these medical advice serve to help address the root problem of your skin condition.