Your quote from the Chicago Sun answers your own question of "Why?".
I find it absurd that any Christian would hold the Jews as a whole responsible for the death of Christ. The Jewish leadership of that day fulfilled a role, just as the Roman government did, if one is to believe what the Gospels say. Again, divine fate or destiny comes into play.
In the same breath I also find it absurd that any Jewish beliver would continue to grab blame that isn't theirs to grab. Instead of coming out and saying "Yes, certain Jewish leaders 2 millenia ago did a number of things that wouldn't be condoned today", the Jewish representation of today has to rush out and paint anything that potentially shows their religious forebearers in a bad light as "Anti-Semitic".
Neo-Nazi's marching in the streets shouting slurs and slogans against Jews is anti-semitic; recounting biblical history (even if there has been some artistic license that's been taken in spots) isn't, I'll wager, unless Mel went off his rocker and just wrecked the biblical accounting with his own version of things...
At the risk of sounding trite, the Anti-Defamation League would have been much smarter in asking that the whole of Christianity thank their ancient forebearers for playing a pivotal role in the salvation of mankind. Otherwise, how would the Christian concept of salvation work without the death of Christ?
