That said, I think the brass did absolutely the right thing to recover from the SSgt's jackassery. I wonder what the reaction would have been if Rumsfeld did that after Abu Ghraib.
And the reason that Muslims are so "batshit" over the Qur'an is that it's more than just the Bible. If Christians believe that Jesus was the Word made flesh, then Muslims believe that the Qur'an is the Word made into a book. To them it's more than a Bible. It is the literal Word of God, the
logos itself if you are of a philosophical bent.
Also, Christianity as a whole is more concerned with
orthodoxy, or right belief, to determine who gets into Heaven. This is exemplified in Matthew 15:11. Muslims are more concerned with
orthopraxy, or right actions. As in the person who gets into Heaven prays 5 times daily, eats only halal food, gives alms, goes on a pilgrimage to Mecca if able, etc.
So the form as well as the substance is very important to them. The Qur'an is thus never handled without washing one's hands, and is always placed in a dustcover on the highest shelf on a bookshelf.
So when you combine all that, it's easy to see why the Iraqis got ragingly pissed over this incident.