To answer your question;
It starts out as a fast track to physical supremacy and to overcome your genetic shortcomings
Then the strength and physical changes, not previously achieveable, leave no question in the users mind that another cycle must be done.. usually too early
After that, the inexperienced will determine that working out while not 'on' is pointless and a waste of time and to be seen while not in peak physical shape would bruise the reputation as a gym 'animal' and nightclub 'rager' and deflate the ego beyond repair... so he'll continue to use regardless of health, relationships and monetary cost