Cultures don't mix well,
I think it's about time we just realised this instead of trying to force it down peoples throats.
My opinion is, Islamic people want their own law? that's cool with me but do it in your own country. Don't try think that anyone here wants it.
There is nothing wrong with different cultures, but I think when you try to live with someone who has radically different views it just creates tension and causes clashes. This even goes further than culture, for example I used to have a house mate who was incredibly negative and always saw bad in things. Whilst I sat there trying to see the good (As best as I could) and stay away from negativity. What happens? I isolate myself away and it just creates a division and sometimes can end in tension. I think it's just the way we are.
I notice often people naturally also tend keep to their own kind/mindsets/cultures. It's natural for human beings to seek comfort so they isolate themselves with other like minded individuals where they feel a sense of belonging.
Cultures can mix, but it cannot be radically different ie shariah law, burkas etc etc.