Not that I wouldn't like to be as optimistic, too, but Nature does seem to have made enough use of unreliably folding proteins to have come up with BSE, Parkinson's disease, and some others <http://en.wikipedia.org/wiki/Protein_folding#Incorrect_prote... >.
I'm a big fan of Scott Aaronson, too, btw :-) Here's a pic of him demoing the soap bubbles experiment he refers to in that paper you linked to <http://www.scottaaronson.com/soapbubble.jpg >.