A better question would be "why the poor buy a $1500 sofa"?
Almost all loans that don't feed into some sort of income producing activity are bad loans.
My parents taught me not to buy things I couldn't afford to pay in full immediately, because loans cost you. With the exception of my house, I have never taken out a loan. I pay my CC in full every month. Why do poor people feel they must have new, quality furnishings? I can see the rare splurge on something nice, but it seems everyone has to have all sorts of nice stuff regardless of whether they can afford it or not. Craigslist makes it ridiculously easy to find affordable furniture.