The concept seems odd to me. I think it always did. I am allowed to kill some lesser creature and spill its blood upon the ground, and God will forgive me my transgressions. We bypass this today because God offered to sacrifice a human body, one that he (or His son) temporarily inhabited before returning to Heaven. To a being older than time itself, this interlude was so short, it is difficult to imagine that He even noticed it.
What I wonder about it is... could Jesus have failed? Was there a possibility that he would sin, and thus condemn humanity to an eternity of sin, suffering, and death? What would happen to Jesus/God if this had happened? What would have happened to Satan? If Jesus's triumph was inevitable and Satan's defeat guaranteed, why was the sacrifice even necessary? Who did Jehovah feel He needed to impress?