Why is it such a shock to people that yes, in Muslim countries you get Muslims who are Muslims in name only and Muslims in who pray 5 times a day every day with extra optional prayers in between. Someone correctly pointed out above that irreligion rates are higher than reported. Pakistan reports a 97% Muslim population - of that population probably half is barely practicing. Most Muslims probably are just Friday Muslims like your Sunday Christians.
The growth of the overall Muslim population is generally decreasing in countries where living standards are improving, urbanisation is occurring or has occurred, and where women are participating in the workforce as TFR falls.
Also, if you think Pakistani (specifically Pakistani) immigrants are a danger to the US, you must be living in an alternate reality. Next you're going to tell me Sugar Land is a Sharia zone