Maybe because the true God, is trying to bring them back in the fold, and thus what they follow is so off key, everyone has been trying to correct them....
So instead of learning from it, and questioning maybe they've been following the wrong path; they've become hardened, and set in their ways......
So an example of this would be Yeshua, who came along challenging Rabbinic Judaism saying it was not of God, yet of man....With its obsessive ritualism, temple obsession, prayer mongering, over zealous cleanliness, etc...
So now 2000 years later all that is left is their Rabbinic Judaism....