Jews don’t believe in Jesus because he’s total bullshit.
Jews are pretty good at detecting bullshit and they realize that believing in Jesus is a pretty bullshit thing to do.
That said, religious Jews also believe in a host of other bullshit, like the fact that they are the chosen people, that they were slaves in egypt and were magically freed, and that God came down on Mount Sinai and publically gave 10 commandments to the entire people.
Jews are rational people, certainly. But they also believe they they single handedly introduced morality to the world, that Jerusalem is the center of the universe, and that the world was created in six days, give or take 13.7 billion.
Jews are the people of the book. But then again, Christians and Muslims also like to be known as people of the book. And if you consider that sometimes the book in question is 2,500 years old, you might come to realize that might actually be helpful if they expanded their options, effectively becoming people of the books.
So if you think about it, believing in Jesus shouldn’t be that far-fetched, and it does beg the original question – fuck, with all the other bullshit Jews believe, why don’t Jews believe in Jesus?