Arguing against the Islamic state, Mohan Ramakrishnan (' Uncertainty, the bottom line to PAS' proposal ' ) wrote this:

"For a multiracial country, lawmakers have to be and have been sensitive towards its people, their needs and beliefs, and should keep from imposing rules that do not coincide with their religious teachings, beliefs and practices."

It appears that this only applies to non-Muslims, but not to Muslims who believe that Islamic law is part of their belief. Unlike other religions, some of the existing laws are in conflict with the Islamic laws. Justice is sacrificed when you want to make the laws uniformly applied on all sections of society who have different sets of belief.