If you know that Jews aren't Christians, then why do you think they'd care one whit about what various Christian doctrine's say about their temple?
Their church building is missing, and it makes sense for them to rebuild it.
John 14:6
Jesus saith unto him, I am the way, the truth, and the life: no man cometh unto the Father, but by me.
This is why they should care. They are holding to a religious system that is no longer authorized by God.