I would just say that anyone lending coins in order to get a 1% or 2% interest is making a huge mistakes. With the number of scams and ponzis going around in the cryptocurrency market, this is probably the stupidest thing to do. For example, you are lending 1 BTC to someone and expects him to pay 1.1 BTC back within one month. Now let's look it from the perspective of the guy who took the loan.
Darkstar's loan business is going well so far. And the same thing could be said about banks. They keep loaning their money to people, and so far, it works great for them.
Bitcoin is not going to multiply itself. So either this guy is planning to run away with the coins, or he is planning to use these coins for some investment (trading or ICOs) a nd expects to net a profit. Even if it is the second case, there is no guarantee that the coins will be paid back in time. What if he incurs a loss in trading. Then how he is going to pay back the coins? Will he take another loan to cover the existing loan?
Or he could use other coins or tokens to pay back the loan. Or he got his salary next month and paid for it. You can't lend your money just to some random guy. It's stupid.
You need to understand that loan is not the same as free money. Most of the time, you need collateral before somebody gives you a loan, so the risk of them running away is smaller than you expected, except the collateral does not have any value.
The lending game in crypto is tough, and that's why there haven't been any *legitimate* crypto banks yet that pay interest on deposits. There was that bitcoin savings & loan some years ago, but that turned out to be a huge ponzi scheme.
It's no secret that fiat lending is more structured and regulated, hence the number of scams could be lower than crypto. But using a small part of your Bitcoin might not be a bad idea at all if you can manage it.