Drug or no drug, it does this
'When artificial testosterone is introduced into the body, the pituitary gland in the brain senses its presence and shuts off the supply of hormones that stimulate the testicles to make their own testosterone and sperm. The brain cannot differentiate natural testosterone from synthetic, so it shuts down its own sperm-making mechanisms'.
http://www.nytimes.com/2005/06/20/health/menshealth/20alexander.html?pagewanted=all&_r=0
Why take it if you don't need it. Ok, some may want to lift more weight; maybe some want to look good and pick up chicks (or guys); or maybe some need it because their gonads dont work well enough.
I am lucky; look good (my opinion), still can do the deed regularly; and don't need drugs to give me that extra 15% in weight in the bench press and other lifts.
You could be right though. I am near 52, and my best days are behind me. Maybe I should be more tolerant of others who don't share my good fortune (I now have a sound body and sound mind).