Jesus was sad about it.
Luk 19:41 And when he came nigh, having seen the city, he wept over it,
Luk 19:42 saying--`If thou didst know, even thou, at least in this thy day, the things for thy peace; but now they were hid from thine eyes.
Luk 19:43 `Because days shall come upon thee, and thine enemies shall cast around thee a rampart, and compass thee round, and press thee on every side,
Luk 19:44 and lay thee low, and thy children within thee, and they shall not leave in thee a stone upon a stone, because thou didst not know the time of thy inspection.'
I don't think He was weeping over a city that was some 2,000 yrs. out in the future. I believe He was weeping over a city where He had brought them, "the things for thy peace". The place where He had said...
Mat 23:37 `Jerusalem, Jerusalem, that art killing the prophets, and stoning those sent unto thee, how often did I will to gather thy children together, as a hen doth gather her own chickens under the wings, and ye did not will.
Mat 23:38 Lo, left desolate to you is your house;
I asked myself, if Jerusalem today is killing prophets and stoning those sent to them? Even the Orthodox Jews in Israel as much as they dislike the Messianic Jews are not doing this today. In fact, do the Jews even have any prophets today to kill?
Luk 11:51 - From the blood of Abel unto the blood of Zacharias, which perished between the altar and the temple: verily I say unto you, It shall be required of this generation.
Zacharias son of Barachias may have been their last. He was killed by the Zealots(radicalized Jewish extremists) in 67AD, so in effect this is Jesus prophesying the final murdered prophet before Jerusalem's tribulation at the hands of Rome.