i have asked myself the same question before, how strange! i thought i was the only one.
anyways the way i was able to make sense of it was through my own situation when i was growing up and being told that there is a God and he made the world, so i never thought any differently (until college) because that's just what i was told throughout my life.. so
if you were told your whole life that suicide bombing is what you should do and it's heroic.. and you didn't go to college or have people suggest that it may be wrong.. then you may believe it for a long time.
so i think in that case.. they are innocent.. if they are young..? idk...