Idk, because altho it was a horrible thing, Jesus completed his plan to replace the scapegoat, and take on all of our sins so that we may be cleansed through the acceptance of the gift of salvation that Jesus freely offer us?
Becouse Jesus the son of God sacrificed his life for us all. Sacrifices are good (not bad), am I right? It's called Good Friday becouse of all the good God did for us poor sinners.