Why? Because it effectively cancels all personal responsibility. Nobody gets blamed for mistakes because nobody does anything on his/her own hook. Triangulation, thy name is heaven.
Jesus was sacrificed and, unlike Isaac, there was no surrogate for the Father to slay. Instead, to lessen the distress, the Son was brought back to life.
So, this post made reference to surrogacy, the handmaiden of the ulterior motive or the practice of indirection (triangulation).
It occurred to me the other day after reading a description of a deep sea creature with multiple appendages, each of which have a separate function, that humans follow the same pattern. Except, while half the population has five appendages, the other half has six.