It serves both purposes GF. I dunno if either was intentional. I've heard speculation that his knife came from one with a broken tip. I believe it would be hard to tell for sure. He tells stories about designing his hatchet, having it made, and traveling to pick it up. Even lists the cost, admits its assinine, and mentions his acquaintances teasing him about. Yet, no mention of the knife really except to say it needed to be thin bladed, and well made. Maybe HD can shed more light on it. He knows a considerable bit more than I about it.
I will say that the ones I've made, the shape is a winner. If the blade is nice and thin and the edge is convex, the slicing power is amazing. The belly helps with this. I even use one as a skiv knife for leather (bueno).
I've done somelight 2x4 chopping with it just to test the edge, and they've held. But a chopper it isn't, so I'm not sure the weight forward thing makes much of a difference. Again, others know vastly more than me on this.