That's breaking even at a ~5.83% default rate, which is still unrealistically low. If they have a default rate of 20%, they'd need at least 240% APR to break even (assuming 1 month loans).
For me? No. For someone in poverty eating ramen, mac-and-cheese, and rice/beans all the time? Sure. $20 is a lot of money for plenty of people in this country.