I believe there can be technical challenges and luck involved in climbing 8000m peaks outside of the $ challenge. Also, it does take a fair amount of physical conditioning, though more within the realm of possiblity for more people than climbing 5.14. Of course, since I've done neither, and most likely never will, I'm talking out of my ass.
It is definitely an accomplishment, but perhaps a little more of a numbers chasing game than climbing for fun, but maybe that is just what floats Mr. Viestur's boat.