The only plausible reason for this I can think of is disrespect. Jesus was a jew, so ultimately a jew is the savior of every christian there ever was and shall be. Jews don't believe in Jesus as their savior but do recognize him as a person. With those two things being said, it seems like one major religion is publicly contradicting another major religion for sheer publicity. Basically the pope is offering Judaism stale forgiveness and possibly pity.