There is a lot of animosity towards those who practice Islam - even those who have lived in the United States all of their lives. After the 9/11 terrorist attacks, Muslims are put on the same pedestal as the radical Jihad followers who perpetrated the attack.
The sad realization is that many in the Islamic world frown on what happened to the US, but rather than be sympathetic our treatment of the Muslim society has caused them to put up their own walls, too.
So why can't we just get along? I am sure we wouldn't take too kindly to a group of Islamic individuals burning our Bibles during Christmas (or any time of the year) - so why burn a Quran - especially during their Holy Month of Ramadan?