You have a good point, this device certainly doesn't take the digging out of the equation when you are in the middle of nowhere with no other anchor point options. We have done all of our testing in soft sand since, to us, it is the most difficult thing anchor to. Also we live in San Diego, we don't have the kind of terrain you are talking about. Any denser ground than soft sand will not require as deep of a hole though. We have dug it into the clay of a crust on top, slick mud underneath lake bed. We dug about 14" inches and buried the Deadman. We were able to achieve a load of 2700lbs before our grip gave out, it didn't budge.
The second video on the kickstarter page is going up a soft sandy hill with rocky hard pack at the top. We dug down about 18" for that video, once it got set it didn't move during the entire pull.
Digging a hole in any terrain would not be our first option. If we could grab a large rock or a tree, that would be what we would go for first. But if we don't have those options, at least we could still bury it.