the comfy softshell upper isn't tough enough to hack it on rocky terrain, the EVA midole unit gets scragged by passing boulders and the sole unit has about as much stiffness as a freshly landed dover sole.
Similar criticisms could be aired at my Tevas, but I've done the Aonach Eagach (and much more besides) in those with no particular issues or problems, and I think that counts as "rocky terrain"... Unless you're doing foot jams, running looose scree or warding off tournquet effects of crampon straps I don't find uppers need to be anything special, or (as is the case with sandals) even present.
While I agree on the whole with the points in the 'blog, the other side of it is I think we need to get away from the feeling that you need serious technical kit for anything beyond an amble. They might make life better for some folk, but that's not the same as necessary... The SNH website for Corrie Fee tells you "sturdy footwear should also be worn as this track accesses a wild mountain environment and is uneven in places"... walking up there to get married I was in a pair of brogues to go with my Prince Charlie and my wife had a pair of sandals with her wedding dress!
While better safe than sorry, society as a whole these days does worry far too much, and increasingly seems to think you can't walk around a country park without £500 worth of technical gear.
Pete.