Because many people look to replace a camp axe / large / small knife combo, or any combo of the three, with a single knife, or a large knife and a very small knife.
The axe has its advantages, clearly, but a large knife is more flexible when it comes to what it can do.
Of course, we are talking about knife theology here, so opinions will vary drastically, but the bottom line is that a lot of people baton using their knives, a decent knife can baton for a lifetime, so why not, and people want to see it, so I do it.
Furthermore, what is the point of purchasing an expensive knife, if not to use it for hard tasks? If I didn't need my knife to be tough, I would just purchase some pos. But a large knife chops, and batons, and breaks from both uses are possible. If you don't want to use a knife for either, than there isn't much reason to own a large knife anyways.
