I won't argue that, but I think the trend data makes a convincing case that Reddit's rise and Digg's demise were inevitable, regardless of Digg's redesign failure.
Perhaps. Had they handled the redesign correctly, things may have turned out differently. It was a perfect storm of design, technology and technology failure...
I.e., Reddit was doing something right, and Digg was shrinking. The Digg redesign fiasco accelerated both trends.