Show me in scripture where it says Moses liked spaghetti. It isn't there, but that doesn't mean its true. Are you really going to rely on an absence of evidence argument? The Moshiach is, according to scripture, going to fulfill a series of specific prophecies, and then rule as a King. It doesn't say 'he'll die first, then finish the job'. The onus is therefore on you to supply evidence of a second coming.
Listen, one of your great rabbis - Maimonides (Rabbi Moses Ben Maimon) - said about the Messiah in Daniel chapter 9: "Daniel has elucidated to us the knowledge of the end times. However, since they are secret, the wise [rabbis] have barred the calculation of the days of Messiah’s coming so that the untutored populace will not be led astray when they see that the End Times have already come but there is no sign of the Messiah" (Igeret Teiman, Chapter 3 p.24.)"
That's right. First the Messiah is 'cut off' (killed, and matches Isaiah 53:8 - "For he was cut off from the land of the living; for the transgression of my people he was punished..."), AND THEN, AFTER THE MESSIAH IS KILLED, the following is written: "
War will continue until the end, and desolations have been decreed."
Does that sound like a Messiah who ushers in world peace when he first appears on the scene? No, it doesn't.
So, here's the order from Daniel 9:
Jerusalem will be rebuilt.
The Messiah will appear.
The Messiah will be cut off / killed.
After that, war will continue until the end.
It fits the Jewish Messiah Jesus perfectly, but not the Jewish Messiah who will appear and immediately bring peace to the world. You guys have it out of order. Which is why you had to create two Messiah's (Messiah ben Joseph and Messiah ben David) to try to explain things.
Remember, one of your great Rabbis understood Daniel 9 spoke about the Messiah, and he wasn't the only one.