It is the easiest way to avoid a scam. But few people who really need a loan and doesn't have valid collateral (the only altcoin is valid collateral according to me), lenders usually consider that (I think). I have seen several Reputed members even DT1 took a loan without collateral. And maximum reputed members are very honest. For example: actmyname asked for a loan of 0.25BTC without collateral where 2 people send so total received 0.5BTC. actmyname refunded 2nd sender. And repaid early to the first person. I also gave actmyname a loan of 0.25BTC without collateral and repaid on time as usual.