Why?
And this was exactly the case before Muhammad came. Jews and Christians expected him to appear in this region. But this didn't help most Jews and Christians because Muhammad was not a Jew and nor did he say he was Christian. Both had then already lost their originality.
Prove this statement without appealing to a book that has been shown to be plagarized from Hebrew and Christian sources.
So the problem is not the prophetic signs but whether people are really ready to embrace it. There's always a third way for man to hide truth and the interesting thing is that he can do this with a belief that he is on the right side. This is only deception of course.