Denial of form I-765 marriage based?

I have received the letter that showed that I have been denied the Authorization for Work because :..." you are currently in removal proceedings before the Immigration Judge. It would be inappropriate to grant...who is currently in immigration proceedings or waiting to be considered by the immigration court". It is true. I have a pending Asylum Application whith the date of June, 2011, for the court hearing and immigration proceedings. However, why I am not allowed to work while my I-485 is pending?