A survival knife in your pack with your tarp, extra clothes, sleeping bag, snacks, etc doesn't make sense to me.
Speaking as a (wannabe) alpinist, carrying a knife in the pack makes perfect sense to me.
A story... A guy I know was skiing a backcountry XC route out of Waterville Valley, NH several years ago. He was skiing along a flat section of an old logging road and took a simple fall. Possibly hooked some dead fall beneath the surface but could have just "caught an edge". He landed and ended up with a double spiral fracture of his femur - one by his knee and the other by his hip. It could happen to anybody.
He fell in the late afternoon. He was a short 2 miles from reconnecting with WV's busy trail system and about 5 miles from the road. He had a parka, bivy sack and satellite phone in his pack. But, he was so incapacitated with pain that he couldn't get his pack off, much less access anything.
This is pretty much my nightmare scenario. A simple fall at the end of the day heading into a frigid night. It's one reason why I prefer to travel in groups of 3 for backcountry ski trips. This trip was 10 miles all of which was separated from the road by a river with no good crossing options (except at either end).
Untitled by
Pinnah, on Flickr
We carried a small wood stove, bivy sacks and a tarp, plus heavy parkas. 3 people: 1 injured, 1 to tend and 1 to get help.
For trips like this, there is a balance between too much and too little. Tricky balance.
But one thing is for sure...
EVERYTHING in my pack is about surviving the night. Everything. There's no way I'm going to survive with what's in pockets - so much so, that I never ever even think about survival away from my pack. The conditions are too bad and the margins too thin to begin with.
There are things I want on my person but it's really more about convenience. If I'm in the woods, I have a pack.