well you have to make people uncomfortable and scared when interogationg them. it's a no brainer that would be cultural. I wouldn't blast rock music at a head banger but a mozart fan....
In a normal situation, there are things that can be offered or threatened, in order to make a deal
but when one's crimes are so terrible, and when your dealing with someone who is probably willing to die for their beliefs, the same kind of deals/threats simply won't work.
and when your dealing with the possibility of catostrophic damage beyond the scale of the vast majority of regular criminal activity, you need info and quickly
and if you allow them to lawyer up, with this lack of an ability to make deals/threats, then there will be no information and you're fucked.