You just nailed it, spot on.
Except those who buy multiples of the same knife, and don't want a pile of sheaths, at extra cost.
The knives cost what they cost. A sheath has an actual price. A cost associated with the making and supplying of a sheath.
Busse has offered sheaths in the past.
A lot of their core buyers want custom sheaths, and don't want the cost of the sheath added to the price of the knife.
I make my own leather. When I want Kydex, there are a list of custom makers that cater to Busse/Scrapyard/Swamp Rat fans.
There are also a double handful of custom leather sheaths makers that do the same. Many of these makers, leather and Kydex, keep Busse models on hand to make sheaths for them.
Busse is doing a favor by not making my pay for a sheath I may not want.
I temper a member buying 27 of the same model knife from Busse. In one order.
He sure as he'll did not want 27 sheaths.
Some of my knives end up with more than one sheath for them.
I've owned multiples of a specific model. But I did not carry them at the same time.
I buy what I want. You do the same.
Maybe, some time you can buy a knife, and then regale us all with your opinions.
I'd love to see it.
I promise, no one laments the fact that you won't buy a Busse.
I have had Busse knives come with sheaths. Including Basic sheaths they used to offer on their site. I ended up never using the basic sheaths. They were items I did not keep.
There are many custom knife makers who won't make you a sheath. They make knives, and leave the sheaths to othere custom makers they recomend.
I have a custom that came with a sheath, and the sheath is terrible. Like a child made it. I'll just make another. But when a maker does not make sheaths, I'm just fine with that.
For your car analogy.
I was shopping for a truck some time ago. I was looking at used trucks.
The dealer kept trying to push me towards these trucks that they had "upgraded" the wheels on.
The dealer had a handful of trucks that they had put 20 inch or 22 inch rims on.
On 4x4 trucks. I explained I don't want to spend extra money on rims and tires I don't have a use for.
If you have ever seen anyone off road on 22 inch rims, you learn very quick that the larger rim is a hindrance. Pinched and torn out side walls increase in frequency the larger your rims get (unless you are also going up exponentially in tire size to tires that are monsters).
Also, if you have ever shopped tires you know that that the same tread pattern, in the same size/diameter tire, but running a larger rim is much more expensive to replace.