Steve-O does not run the show or choose the stunts. The comments here directing the frustration over this toward him are mind boggling.
Also, I remember the Fear Factor thread. The guy who supplied the snakes actually made an account here to explain that they practiced the stunt multiple times to make sure the contestant understood how to keep the animals safe and they rotates snakes in from a van full of racks with proper conditions to make sure that no single snake was subjected to stress for an extended time.
I do NOT condone the video or the practice, but I agree with Kinra that I think a lot of the 'animal abuse' claims can be chalked up to reality TV gimmicks. These people have a LOT to lose if someone cared to prove them to be abusing the animals, so I do believe they have themselves covered on stunts like this. Perhaps we should blame animal cruelty laws? I am unaware of them or if they change based on species or anything, but I could see them making stricter laws for dogs than reptiles.