One person's defamation is another person's whistle blowing.......

there are all sorts of cases where questioning the status quo or the commonly held belief systems was initially seen as defamation- but it had to be done.

Also, if Islamic countries are so secure in their beliefs, and the faith of their people, they shouldn't be effected by critism- to the contrary, critism can only strenghthen beliefs, as they become more than just the thing handed down to you. Fear of critism is a lack of security in the things you believe in.