We don't capitalize God because there is "only one". They are actually different words. They have different meanings. The word "God" capitalized means "The Ultimate Reality". Uncapitalized it means something else, some of which are even gods we acknowledge to have some reality to them.
When the artist wrote on the back of a cereal box, was God their inspiration or did they find their muse in cornflakes? When Shakespeare wrote his plays, was God his inspiration or human experience?
Certainly, you could say that God created all things, but we Orthodox don't even believe that God dictated the bible. It should be obvious that the personalities of the authors are present in the writings.
Muslims believe the Koran was dictated in this way. Maybe some protestants do too. We Orthodox would see that as a type of idolatry.
That said, we do revere scripture, but we also know what it is used for. It is, after all, a product of our church tradition and a part of it. It is our book(s).