There is nothing wrong with burning a book. However, this is not just a book to some people. It is a disgraceful and hurtful act. The Muslims are already on edge as it is, and this will contribute to their outrage. No holy books should be banned because it goes against cultural values.
There should be no ban on burning the Quran as it sets an unfair precedent. If one book is protected, then why shouldn't other books also be protected? Banning the burning of the Quran would open Pandora's box in this regard, and it could lead to the infringement of free speech.