Not really, considering the amount of steroids that are taken by them. They arent "forced" as such, but the stress that constantly being on the road has on them means that to keep their bodies going with the schedule they have, they resort to Steroids to keep them going. Another reason could be the lifestyle they live, very glamourous on the surface but very dark and full of drugs. Look at Guerrero, he was a heavy drug taker, before sorting himself out, the drug taking eventually caught up with him and hence his death. If the Steroids hadnt made him aggressive and kill his family, he would have died in the next 10 years or so anyway, its just the way things go with steroids. So, no it isnt surprising to me.