Because the wisdom of God, the wisdom of the Cross, is shown to us in what Love Does. Love Does. What Love Does is be crucified. What Love Does is to climb up on the cross and be crucified, by both the Romans and the Jews, working in tandem together.
For the message of the cross is foolishness to those who are perishing, but to those who are being saved it is the power of God. I Corinthians 1.18