I agree with the "protective coloration" idea - if security people are willing to consider a nail file as a viable weapon, imagine what they'ed make of something that looked purpose-built. I can see it now ... "OK, buddy, up against the wall and spread 'em. We've got you pegged as a terrorist because that little item that YOU called a survival kit has all these deadly weapons it it - fish hooks to put someone's eye out; a razor blade; fishing line you could strangle someone with; matches for bomb making; Portable Aqua, God knows what evil thing you were going to do with that ..."