Jacoby is Jewish, not Christian, and therefore does not have within his religious tradition the commandment “Love your enemies.” Obviously, repentance is necessary if forgiveness is to be received. But that’s hard for the dead to do. The Christian command to forgive wrongs done us is absolute. We are to extend forgiveness even to those who do not receive it or expect none ourselves. In the case of the dead, we commend them to the mercy of God (as the Pope did) and ask that he judge them mercifully.
Think about the alternative: Lives blasted with bitterness and the gall-suckled memories of wrongs done by long dead parents, teachers, siblings, schoolyard bullies, and foes of every sort who never repented (who perhaps never even knew they needed to). They continue to dominate us till our dying day because we refuse to extend forgiveness to them and hand them over to God.
There’s a reason Jesus describes the punishment for unforgiveness as “being handed over to the torturers”. You are handed over to the ghosts of the people you refuse to forgive. It’s like choosing to watch a film you hate, forever.