Are we too accommodating of religious laws?

I am referring mainly to this plan by the National Australia Bank to introduce “Muslim friendly loans.” These loans are designed to bypass Islam’s teachings on usury. It makes loan recipients immune from interest rate changes, and (I think) far more financially independent than the rest of the population. I am not very knowledgeable about economics, so I would appreciate an explanation as to how it would affect them financially. Would the same thing happen for Scientology, or other smaller religions? Do you think it is a good idea, or not?