From what sashan says, I see that he does it partly out of altruism, but many times to get out of the hole as you say is as easy as tightening the belt for a while, which will be more or less long depending on the size of the hole. But the thing is that when I see people asking for a small loan, and after paying it back they ask for another one, and another one, I tend to think that things are going to end badly. It is not necessarily so in 100% of the cases but it indicates a bad management of own resources and not knowing or ignoring basic rules of personal finance.
There's someone right now on the Lending board, who takes larger and larger loans right after paying one back.
I've seen it many times, both online and IRL: taking as loan once, paying it back with interest, and never doing it again can actually help someone. But doing it on a regular basis either drains your finances, or you're not planning to ever pay it back. Either way, it often gets worse after a while.