A blockchain can be used to create a cryptocurrency to act as a medium of exchange.

A blockchain or cryptocurrency, IMHO, cannot vette people for loans, and then prosecute them if they are fraudulent in their loan application and/or don't pay the loan back.

I think any of these coins based on that concept is doomed to fail (WeTrust, HumanIQ)

If you want to do something like this, use an existing coin as the  currency, and then create the software etc to facilitate the peer to peer loans (ie, create a Kickstarter using Bitcoin or Monero or Dash or some other coin, and let that software run in a de-centralized fashion)