SSPX is concerned with the fact the Modern Catholic Church teaches Jew they can be saved without Jesus, Jesus said, I am the way the Truth, and the Life, no one can come to the Father but by me. Thus, the Church has always taught, Outside the Church, there is no salvation. Individual Jews must believe in Christ, personally, as Savior and Lord, they are being lied to by modernists who defy the Traditional Catholic Faith.
Catholics must share the gospel, the traditional faith teaches all who refuse belief in Christ will be damned to hell. Therefore, SSPX is showing mercy by letting the Jews know, they are in grave, present danger of eternal damnation. Vatican II has really watered down the missionary imperative of the Church, its teachings, violating the traditional faith are false.
Didn’t you know that was an anti-Semitic teaching? ;-)