4 1/2 is nothing even close to a pigsticker, especially when you have a steel shard pointed straight your neck because its "supposed to go there". And really, the pigsticker thing is taken completely out of context these days anyhow, a pigsticker refers to a spike bayonet, and the term was coined by troops WWII era using a L-E No. 4 Mk1, with its easier to manufacture spike bayonet. If you want to talk about the carrying a small "sword", its what all commonwealth troops carried until 1941, with some as long as through korea, in the form of the 1907 pattern bayonet for the SMLE, a full 17 inches of blade with overall length topping 22 inches, but I digress....
What is there wrong with having a useful blade in an accesible location where it will not get tied up, what works for some will not work for others, that is without question, just attempting to say what others have done and found useful. If you want to make fun of someone for doing something they find to be effective, then really all your doing is curbing ones desire to make things better for themselves, and in turn, just maybe, for others. I know thats a stretch in this context, but really, let the guy experiment, nobody here has told him to get a Ka-Bar or a Jungle Primitive, a machete or a katana, the troop will experiment and find what works for them. For some of us, its belt mounted, some its in the pocket (folder), some of us its the vest. Personally i hate having my belt being pushed up when i sit because my sheath is making contact, so the vest works for me, but thats not to say it will work for you. Necessity is the mother of invention, but tinkering, IMHO, is its father.