It would appear that at some point the erroneous belief emerged that the words of the Quran had been directly dictated to the prophet by God. This prevented serious study of the language and subsequent translations to remove errors and develop more evolved understandings. It fucking explains a lot regarding the obvious differences between Islam and Christianity/Judaism in so much as how they are acted out in the modern world.
Catholicism was a warping of Christianity that almost rendered it inert by forcing a human intermediary between the faithful and God. But even Catholic clergy knew that the Bible had not been dictated directly by God - afterall the new testament is clearly a series of eye witness accounts and letters between early leaders of the church, plus likely a bunch of stuff added in the centuries leading up to the Roman conversion.