Because I do not accept that premise. I see it as fundamentally flawed for several reasons.
1) There have been many worthy Hebrew scholars through the ages who happened to be Christians. When it comes to the technical issues of translating Hebrew into other languages, they can stand with the best of them.
2) The post-resurrection rabbis have a vested interest in downplaying the prophetic Scriptures as pointing conclusively to Jesus Christ. This should come as no surprise to anyone who has read their writings.
3) The apostle John provided the infallible/inspired interpretation of Zech 12 when he applied it to Christ on the cross. This is true of all the NT writers. The constant reframe of “for these things were done that the Scripture should be fulfilled” is not unique to John. Proving Christ was who He claimed to be from the OT was the task of the NT writers under the inspiration of the Holy Spirit. The post-resurrection rabbis’ interpretation was not at the same level, and does not carry this divine authority. Physical genetics does not trump spiritual genetics. God the Father provides His people with the means to understand His word by imparting the Spirit. The rabbis who deny Messiah has come in the flesh do not share in that blessing.
One thing I may not have explained to you is that I originally believed much the same as you do. … I understand that you have your view but I would suggest that you spend some time researching the dispensational side.
And I used to be a die-hard dispensationalist. I have studied it extensively and I know its many weaknesses. It starts with a fundamentally unbiblical premise -- the radical distinction between Israel and the Church -- and then deteriorates from there. E.g., The rapture doctrine was invented to support the basic theory.
The thing I find most irrational about dispensationalists is that while they claim to take OT prophecies literally and criticize those who spiritualize OT prophecies-- clearly Jesus and the Apostles spiritualized OT prophecies and they accept those interpretations as legitimate but cast aspersions on Christians who follow Jesus and the Apostles method of interpretation.
>> the radical distinction between Israel and the Church<<
I don’t know why you call it “radical” but there certainly is a distinction made in Scriptures between Israel and the Church. Christians have been grafted in as far as the promise of Salvation and family are concerned but the promises made to the Jewish people were eternal. Even in the book of Revelation Israel is separate. http://www.israelect.com/reference/WillieMartin/Israel_in_Revelation.htm