Try entering a calorie defecit and performing increased cardio while NOT ANY ANABOLIC STEROIDS; you will LOSE MUSCLE, plain and simple.
When I am dropping bodyfat, my cutting cycles consist of a minimum dosage of testosterone(200-300mgs) in conjunction with a secondary anabolic such as Primobolan or Masteron, and perhaps an oral to facilitate hardness and vascularity, such as Anavar or Winstrol.
Furthermore, certain steroids DRASTICALLY INCREASE MUSCLE HARDNESS(Masteron, Tren, Winstrol, Anavar, Halotestin), so these steroids are best utilized while the bodyfat percentage is low, so these effects can be seen.
However, I do agree with you Nelson that the primary purpose of Anabolic Steroids is to BUILD MUSCLE MASS, and guys trying to "CUT" for their first cycle or "lean bulk" without having sufficient mass is just ridiculous.