>>I guess I'll be waiting for hell to freeze over before I receive a legitimate answer as to why this disgusting behavior exists.<<
Since I'd hate for you too have to wait until GWB gets' re-elected to get an answer, (

) I will give it a wack, though in truth, I'm only expanding on the answer GOP-Jeff (of all people) has posted for your're edification....
Barnabas Source
Evangelical Christians. The reason their involved needs no further explanation, right?
Iranian Evangelical Martys
1999 UN Report on the Apostate Salmon Rushdie ("Satanic Verses")
Some quick facts from the reading;
The Iranian government didn't kill the 5 evangelical ministers. They have also disavowed any reward for the death of Rushdie.
Several of the Martyrs were locked up under horredous conditions. One was sentenced to death but after the international stink it caused, was released. Four months later he was abducted and executed.
That pattern is consistent throughout all of the Martyrs (Rushdie is still alive). The Government harrasses them to varying degrees (but doesn't follow Sharia up to execution), Then, after they are released from government custody, the death sentence is executed by an apparently non-governmental agent.
After very limited review, it appears the Iranian culture is also struggling with this question. The civil authorities, and one would assume the majority of the people, don't think the Sharias punishment of death is appropriate or expediant (no government execution, no mob of rock throwing zealots, they just disappear one day and their bodies turn up later). I'm guessing the extreme Mullahs whose power in the government comes from strict interpretation of Shaira have to have their pound of flesh, they make sure the apostate pays. The general population would appear to oppose this kind of thing (else why the kidnapping/murder?)
Interesting reading, especially the UN document. The statements of officials of the Civil Iranian Government run diametricaly opposite the Religious rulers statements to the UN investigators.
I'm somewhat encouraged that perhaps, in our lifetime, we'll see this practice come to an end.