Devil’s advocate. Fine hardwood’s actual cash value on the forest floor is roughly zero dollars a board foot. It’s all the logistics, fuel, drying, milling, and marketing that makes black walnut $13 a board foot.
Just two weeks ago I dropped many cherry trees that were straight as a rail in my north woods to improve deer habitat. Didn’t buck them up, didn’t haul them out, just left them to rot in exchange for more sunlight on the forest floor. That’s because they are worth zero unless someone mills them into $7 a board foot lumber. Nobody is going to do that.
So if you’re using a home made chainsaw mill and wasting some wood due to a wide kerf, does it really matter? Better than the alternative of letting the logs rot or dropping $40k on a band saw mill, right? You’ll run out of energy to make boards before you run out of free logs in most species.
I agree, it isn't really the same world. Chainsaw mills are used in places and for trees that can't be cut with bandmills, or by people who don't have that level of investment. The bandmill is the least of it, you need roads, heavy equipment, etc...
This would be an example of where a really wide cut is required, yet a single person could carry the whole mill. Suffice it to say the wood would still be a moving challenge if it outback.
About the smallest log that is worth using for me is a 16" log, and in that case I will sometimes set the first cut to go right through the heart/pith of the log so major waste will we removed by that cut.
Also, what I normally want are thick boards. Low value work, like cutting one's own siding, would see a lot of waste, but my preferred cuts are 1.5 and 2 inches, because they dry quickly enough, and they can then be handled by shop equipment like standard band resaws. Or the product might be worked by hand, like the seat of a Windsor Chair. Thicker pieces, if one can control cracking (never been a problem for me), tend to dry straighter. They are also more valuable per volume, though I don't sell my wood.
So it is correct to point out that the kerf can we waste (though it is a bonus to the soil), but a lot of it is just a mater of thinking through one's options, and planing one's approach, as with anything. The real shame is to see an arbor crew knock over a walnut and run it through the chipper. I am certainly happy that somewhere, someone is efficiently processing 2x4 lumber, but we catch only a small amount of the noble wood that could really find a valuable home if life weren't dominated by plastics.