Buying an interest only house is "renting" under a new guise. Renters don't have the money to buy a house, so someone with wherewithal buys a house and "loans" the use of the house for a fee. The traditional problem with renters is property maintenance. This system solves that. The "renter" has a stake.
He (interest only loan holder) pays hundreds of dollars more a month and maintains the property. The "renter" no more "owns" the house than the old style renter.
These 'renters' do own in the sense that they can sell the property whether they have actual equity or not. If the price is up 15% at the time, they are shrewd indeed. If prices stabilize or decline, they might not be considered shrewd any longer. Roll the dice.