Because in the Bible He indicates that it is meant to be read by us. According to the Bible, that is the manner in which He chose to instruct us. This does not prevent God inspiring us, so to speak. But that inspiration would not invalidate, nor conflict with the Bible.
So the bible is a source of inspiration?
shouldn't have to address statments like this one. We have copies. We do have the Bible. So it does have a useful purpose. I think your logic has broken down here. Let me challange you with a counter question. Why do we need the orignals?
You don't.
If the originals were the only one inspired and the rest are just copies made by men then the very bible you have in you hand is not true.