Interest-free credit is a total nonsense.Nobody would give a loan without any interest.
This guy doesn`t know anything about economics and finance.
Is this Usury thing some other altcoin?
Well to be fair, I think some people would lend money interest free. For example, I bought a car from my parents and instead of paying them they allowed me to make monthly payments with zero interest. Of course, they trust me and that's sort of the core of the issue I think, as @dinofelis said.
but that is different, with your parents it's not only abotu trust but favor or gift, there is no same thing when you deal with a stranger, i also give money to my family and i don't want any interests for that of course, it's my family, would be terrible to demand interests from that, in some case i don't even want the money back