Events like the recent massacre in Paris inevitably resurrect a few talking points. One is to point out that not all muslims are terrorists. A second is to say the moderate muslims need to do *something* (what is never actually specified) about the nuts in their midst. A variation of this is to wonder why oh why haven't they done *something* already.
I'm going on a limb here, but I'm going to guess that the reason they don't do *something* about the nuts in their midst is because of the nuts in their midst. They know what those people are capable of better than we do.
Remember the war on drugs and the war on gangs? We wondered why the people living in the gang ridden neighbourhoods weren't more co-operative with the police. It was because the police were only around sometimes, but the gangs were always there.