One aspect of Muslim culture that runs against the grain of Americans is the lack of the acceptance of separation of church and state. Some (many?) Muslim sects, like the Taliban wish to institute a muslimocracy in which the religious leaders, i.e. imams and such, are also the state. Under Sharia law, it seems that religious texts determine justice in any kind of human disputes, with little regard to circumstances, and with broad interpretation by those who claim to be learned with respect to Koranic law; oh, and with rather crude sentences like stoning.
This kind of society is quite different from one in which there is a civil code that can be invoked without bringing God into the equation explicitly. Certainly, some of the components of Western civil law have roots in parts of the bible, such as the ten commandments. But civil, i.e. governmental and commercial, interests pushed religion from the leading role in Western society and culture to a mostly minor footnote over the last several centuries. Individuals are not judged primarily on their morals or their religion, but rather on what they can accomplish, and how efficiently and quickly they can do it. This leaves many ethical questions to the religious folks to decide, if they don't impact business.
The existence of a civil society fosters the use of logic and understanding, and promotes cooperation to minimize time wasted in disputes. On the negative side of the coin, no moral authority will speak out when the market-makers exploit human ignorance and man's covetous nature to create a dog-eat-dog world filled with meaningless pursuits.
Without a civil society, justice must be haphazard due to the nature of the guidance provided by Holy Books. The Koran is likely no less self-contradicting nor more consistent than the Christian Bible or the Jewish Talmud.
Muslim groups within America appear to be content with the separation of church and state; but, if their holy book says that the believers should make Sharia the law of the land, that is seditious! It speaks against democracy and the human freedoms for which the country stands.
It would be useful if someone(s) familiar with the subject would address this conflict in an open forum. Perhaps there are whole books, or chapters thereof in the literature that have covered this. Does anyone know?