I agree. If I were a renter I would want my money back too. But, I'm looking at this from the eyes of broker, and the broker doesn't own the points, and he doesn't have all the money in hand to give back to the renter. He gave 70% of what was collected to the owner. I suppose the broker could get a bond of some type, carry insurance, or in the case of David who has been renting for a l-o-n-g time and has made a lot of money over the years, he maybe able to self-insure and give back the money. All things to consider from the brokers side.
As a private owner, you have control, you can give back the money if you desire. Maybe rentals with private individuals will become more popular. For me, I rent at a minimum the same price (or even $1.00 or more) than a broker. Usually, people want to pay me less, but maybe if they know I'll refund their money and check my references, they might balk less -- dunno.