Re: Persians
No, its Sociology. And your view that the last community chooses culture over religion is actually a product of biases because youve been around with that community longest and know most about it. Youve seen all odds and ends of that community.
Pull out a geographic map of the Muslim World.
You will find that people have to fuse their understanding of the world with a newcoming thing like religion. You cant just start thinking about it differently from nothing. Yes it can grow on you, but it takes time, and your first understanding of it is through the eyes of your biases/experiences.
For example, in the Hindustani sphere of influence there is more emphasis on rituals, but when it comes to doing actual good between humans, culture takes precedence over religion. Imagine: What is the status of reformed prostitutes or raped women that come from good families? Some are born into prostitution and raped women are not raped due to their own fault. However, even the most constant praying nimazi Desi Muslim would grimace or shy away from marrying such a woman - it is antithetical to his culture. The woman is a used good. Same reason why divorced women have a hard time getting married again, but men have been known up till 1940s (Nawabs) to have multiple wives.
In regards to Turkey there is a difference between North Turkey and South Turkey. In South, people are more Sufistic and more spiritual and have a better understaning of Islamic principles. In North Turkey, especially the part of North Istanbul, people are more affected by the Enlightenment of the Europeans. When you ask a Northern Turk why he is fasting during Ramadhan his answer will be: "Well, it will help clean up my body, etc, etc" mostly materialistic responses.
Persians treat Islam like a Nationality. Not a religion. Anywho Persians have always been fond of wine, pre and post Islam.
On the opposite hand, the Western Muslim understands Islam as "good deeds" like helping old, helping kids read, etc. But Western Islam has less emphasis on spirituality that Indianized Islam does.
Its a philosophic state of mind produced by the geography, culture, and materials available to a group.
Maybe next avatar…