I have to admit I'm confused at this myself.
Hasn't anyone heard of picking up a phone? Increased anonymity doesn't mean you have to be stupid.
That gets establishing the person being a person out of the way (eliminating the problem where someone can simply use a few different username handles, then request loans from the same people - though it doesn't help if the scammer just asks different lenders unless lenders are expected to pool phone recordings), but does not solve the important issue of it being impractical to collect from defaulters - assuming the person's even in the same country. All bad loans I'm aware of could have been avoided by insisting on tighter restrictions on who's allowed to take out loans (with regards to reputation) - this includes using the tools which exist for credit-checking.
The recent gurg/westcoastconnect/kujoking scam was pretty different from previous problems. He had extensive back-stories (one story I was told was that he worked at a small balloon animal kiosk and wanted to purchase higher-end balloons at a wholesale price, but needed a loan to meet the minimum order requirement), gave addresses and other identifying information - but the information was fake. He gave plenty of identifying info (which turned out to be fake), did a few trades prior, and sounded sincere. Perhaps, the lenders could insist the lendee wait to be lent BTC until he receives a paper code at his/her address, then type it to the lender, to confirm where the lendee lives - but then it pushes out many people who want loans for something immediate (many are waiting for bank transfers to Dwolla to clear).