The purpose of the test isn't to show how you can defend yourself from concrete blocks any more so than chopping up a 2x4 showcases how to ward off the rising number of lumber attacks, or limbing some brush is an example of of self-defence against violent vegetation.
It is used to exhibits a certain level of edge durability which can be extended to estimate the level of damage to be expected from accidental impacts in general, and it does so in a way which is easily repeatable by other people as the material being is relatively standard and easily obtained.
As for difficulty, any knife which can't do this without gross damage isn't one which could take exended chopping on harder woods. This got a reputation of being horribly abusive only because of the popularity of the overly brittle high alloy stainless steel blades, and frequent hollow grinds, a recipe for severe problems on any accidently impact, and well illustrated on that particular "test".
Its reputation was in fact probably why it was chosen, as with so many makers calling it abusive it was fairly obvious that it would be a strong promotional tool to be used by Busse as their blades are not significantly harmed by it.
5160 is one of the tougher and more ductile cutlery steels, it would handle this with little problem. I have done cutting with a few of my khukuris that is far more severe than the concrete block test. Specifically for that work you could expect impaction from about 0.015 - 0.045" in thickness depending on the hardness of the khukuri, how hard you were swinging, and your technique.
As for bending khukuris to 90 degrees, I have approached that, and have even rotated them around like the swirl in a candy cane, but not with HI blades.
-Cliff
Huh? Uncle Bill thwarted by a measly concrete slab, who's gonna believe that?