Just my experience, I sharpen a fair amount of soft stainless (mostly on diamond plate)finish on 1K stone & leather strop. The Vg-10 Shuns seem easy in comparison to sharpen. I do most of burr removal on the stone & strop a couple times on newspaper, no problem with burr removal on VG-10. I find that AEB-L is even better to sharpen almost like carbon. Also like the way the Carbonext & Gesshin Ginga take to the stones. Have little experience sharpening very expensive stainless, since it does not come my way ,my better knives are all carbon steel.
They make tons of shuns I would think that they go through a very specific Heat-freeze-lower heat again process. Even Cutco's have a quality heat treatment. The only thing I can think of besides abuse is perhaps because of the large quantity the edge steel is fatigued in the final edge work & has to be removed to get to the good steel. This is pure speculation only a guess. I have had that happen with a stainless Japanese small cleaver.
when i see a knife with as much damage as the one zwiefel repaired, the first thing that pops into my head is people trying to cut frozen stuff with bones. you use a knife with a 'good heat treat' doing the same thing, i guarantee you the damage will be just the same if not worse.
tell them to trade in for a henckels