Ah yes backpacking one of my favorite past times.....I agree that most of the time I never use a blade while backpacking so I usually don't carry much in the way of blades. But a good locking folder could be an invaluable tool when needed.

I think most people don’t pack knives in their PSK. They tend to (me included) carry a knife separate from the kit but part of the kit. When I venture into the woods I always take the least amount of gear needed to safely see me through my journey. On a day hike I have more “survival gear” then on a backpacking trip unless I’m planning an extended trip in a remote area.

I think your right that a big fixed blade knife won’t see much in the way of EDC but a 3-4” folder can easily be carried in a pocket.