“Today many of the Jew have a very difficult time interpreting Isaiah. There are parts of it, such as the suffering servant, that they completely ignore because they can’t understand it.”
The Masoretic text was altered in some cases to follow what non-Christian Jewish leaders of that era assumed to be the most accurate. It is highly unlikely that they made decisions regarding textual accuracy without considering the impact on the debate with Jews who believed in Jesus as the Messiah.
While the Septuagint is merely a good translation of Hebrew scriptures and not the original source, it still may be more accurate in some cases than the Masoretic text.
The main reason Jews today do not pay much attention to latter portions of Isaiah is because the traditional readings in synagogues do not include these sections. And this has to do with history where they were at one time unable to read the books of Moses. Today passages read aloud in synagogues are either books of Moses or passages that directly relate to them as determined by past rabbis.
“Yet Isaiah is the pivotal book which bridges the Old and New Testament and the calling of the Gentiles into the Kingdom.”
The prophecies of the Old Testament not only includes Christ’s death, burial, and resurrection; they also proclaim salvation would come to the Gentile nations through a New Covenant which would be spread through the Gospel, the hearing of faith, the outpouring of the Holy Spirit on people from ALL nations and languages.
Fifteen of 54 weekly Torah portions have haftarahs (additional readings) from Isaiah.