Most physiques built by drugs look unnatural and 'not quite right'. This is why most people find most pro bodybuilder physiques to be 'disgusting' for example. Just like someone would find the elephant man to be unappealing. This is natures way of eliminating these qualities from the gene pool.
People have a subconscious sense when a person has a body that is not possible to achieve naturally. This is brought into the conscious as feelings of disgust. This benefits society as a whole, and ensures that bloated malformed, out of proportioned bodies do not become the norm, as excess muscle mass is costly to the organism energy wise and serves no useful purpose in its survival.