in a way you are correct. most people gain alot of strength on a big cycle and your joints take a beating from the added strain of heavier weights.
another reason is many people do more volume(sets) when on cycle so they are adding more strain yet again through an increased workload.
yet another is people believe they can train more often on steroids so the frequency of training is greatly increased. example - training muscle groups twice a week instead of once due to being on steroids.
heavier weights + more sets(volume) + higher frequency of training = sore joints
when you combine all mentioned above, you will have painful joints. there really is no reason to greatly increase the frequency or volume on steroids IMO. add a little if you like but let them work for you the way they are meant to work.
i have dealt with this mainly in my wrists and elbows from making fast strength gains in powerlifting and Olympic movements.
the human body was not designed to make great jumps in strength and bodyweight. slow and steady gains will prevent injuries and aching joints.
this is my theory backed by many years of kinesiology and anatomy study.
