Because, you may not understand from the many "Zionist stole the land" posts but the Land of Israel is as important to Judaism as Jesus is to Christianity.
Every synagogue on Earth, in all of history, faces Jerusalem. The covenant involves Jews doing certain things and God doing certain things includes Israel as the homeland of the Jews. Some Jewish holidays are celebrated differently- longer- outside of Israel. Ad infinitum
Your natural question would be what happens to the relationship when the Jews didn't have control?
Prayer and observances still focused on Israel.
Think of this- possibly weak-analagy. Suppose a parent loses custody of a child to a kidnapping. The child is always in the thoughts and the love is always there. If somehow the child is restored to the parent, the child would be defended by the parent to the last drop of the parent's blood.
That's the Jewish people's (except for a few crazies)relationship with that tiny sliver of land.
Jesus, being a Jew, must have felt the same about the relationship of the Jewish people to Israel and Jerusalem. It follows that Christians should understand.