over and over again many of the Jews of the Old testament proved that they really didn't care too much about God The Father except just to fulfill obligations and try to rule over the rest of the world. They were unworthy because they were hypocrites and they did not really follow the law, nor did they care about other people, other nations, but claimed special status based upon the whole 'chosen people' thing.
when Christ came the good Jews followed Christ and the other one went on killing rampages and tried to create an empire.
they were vanquished because they were unrightous.
and the descendants have been tainted by that sin ever sense.
when the high priest ripped his robe at the end of the trial of Christ, he broke the covenant and thus the Jews no longer were the only favored people of God.
and then when they went trhough with the crucifiction, the temple curtian in front of the holy-of-holies ripped from top to bottom which was a sign that God was no longer in that temple. God was in the temple of Christ.
Their covenant was broken and the temple was abandoned by God. some few years later due to their pigheaded need to be the rulers they had their temple destroyedd. And then a few years after that they rebelled again, murdering rampages burned down cities, and emperor Hadrian, having had enough of their self-ishness, went and leveled Jerusalem and banished the Jews and banned their cult.