I went out for a short snowshoe trip one day, about 15F, and at my first rest stop realized I did not have any tool for cutting larger wood w/ me. I had a tent and sleeping bag, so was not in bad shape, but was irritated w/ my oversight. I had this mental picture of trying to keep warm w/ a bag that had gotten wet, and not having a good way to keep a larger fire going if required. I had meant to bring a bow saw, as it was light weight and I was pulling a small sled, so space was available.
As I was thinking about the tools I would like to have, or the one I did not bring, never once did I wish I had a large chopping knife. I wanted a bow saw, or a machete, or lastly an axe.
I really do not understand why a person needs a big knife. If I need a large blade, I take a machete, which weighs less than a large knife, can be carried and used w/ less effort, and while chops well, also doubles as a machete, which no large knife can do well. I also like a saw of sorts.
If I can only carry a certain amount of weight due to various limitations, I sure will not waste it on a large, inefficient chunk of steel. If I can carry all the weight I want, I will bring the right tool for the job, not a large, inefficient chunk of steel.
In a few ways I agree w/ shipwreck, take a knife that weighs 7 oz less and bring a silnylon or tyvek poncho. Less energy output and less time required in a true survival situation.
Must say though, that none of my post applies to those who simply want to carry a large knife because they enjoy it. If you do, just man up and say so. Look at Magnussen's kit. He realizes the drawbacks of some of the things he carries, but chooses to do so regardless for his own reasons.
So please, for those who wish to carry large knives, just say you do because you want to, regardless of any drawbacks that may entail. Doing so would certainly save many keystrokes.