To me, a more important question would eb along these lines: if Allah is all-powerful (and He is), why would he not protect His Word from corruption by men? According to Muslims, He did with the Koran but not the Bible. That is crazy. In reality, He would have done both, assuming that both are His Word.
However, we know that the two works conflict with each other on several accounts. Therefore, one must be right and the other wrong, in other words, one must be inspired and the other not. Now, which is which?
Is there logic in saying that the first work was not the work of God and the second was? Not really. Why have any correct information in it at all? How was there any correct information if the Bible if the Bible was not a work of Devine Inspiration? So, the second work must not be inspired. Now, that does not mean that there is no truth in it? No. There is. A good deal of Truth in it is similar to that which was revealed already to the Jews and Christians, and there are some insights that Arabian philosophers added. However, if the facts of the two books are different, both cannot be 100% Truth.
Why would God not protect the Bible from corruption?
If I was starting a new religion, the first thing that I would teach is that GOd gave me the revelation and authority. The second is that all faiths before me fell from the correct path and I am here to correct it.