Hey thanks for opening the discussion.
I know alot of knife enthusists always carry too much steel with them. I carry a Swiss Army One Handed Trekker with the serrations ground down. For me I feel pretty good about this since I have done wilderness and jungle survival classes in Peru. I know what I am capable of doing with a saw, blade and awl of an SAK. If I am by myself I will have a small fixed blade with a full tang that can split wrist size pieces of wood for emergency fire starting when things are wet. Now there are exceptions when I have hiked with a Tramontina 12" machete (10 oz) that is very light and could do almost all knife chores like whittle wood, split wood for dry inside or chop shelter poles, slice and make all kinds of things. Remember that the average big chopping knife or hatchet weigh about 1 pound and a half. There are many people that always feel they have to have a knife in the woods and I am one of them but within reason. When I was going to the Grand Canyon I noticed a few folders clipped to peoples pockets and not much else. I agree with this since you are on heavily traveled trails with not much need for a knife in general. When I am in Lytle Creek CA backpacking or hiking I may not see anyone and the trails are harsh and empty. The chances of being in a survival situation there are high, I have been cought in a horrible snow storm there at 5,000 which is kind of low for snow in the first place. The trails are full of wind blown branches and trees large and small. I always have to saw branches or chop to clear the trails there. It is a place where I see lots of fixed blades on peoples belt if there is anyone in the first place.

Summit attempts.
Not everyone carries an SAK with them but maybe a fixed blade or nothing at all. I was hiking Mt. Whitney last july and noticed many people leaving their gear in the camp at 12,??? feet and making the climb to 14,035 with just water, rain gear and some emergency type things. We usually go very light to make the summit so grabbing a small light knife would be ideal. For those that don't like the weight of a fixed blade like a K-Bar, RAT Cutlery, TOPS, Becker, Busse, could get a small Breeden that weighs 2.5 oz and can do big work.

Cool that was fun.