that's because male pattern baldness is predetermined through genetics. If you recieve the gene for hairloss, then certain hair folocules are deemed dht sensitive, where as when free flowing dht increases(as is the case of conversion with many steroids) it will attach to the follocule and cause it to fall out. Not all hair on a man's head is sensitive to dht. That is why people can take hair foluclues out of the back of their head where they still have hair and implant them on the front of their scalp...anyway, i'm rambling, but just know that steroids don't make every guys' hair fall out...only those with folocules dht sensitve because of the inherited baldness gene