Did you read the article? The point seemed to be that it certainly smoothed out some peoples lives, it did not actually have a measurable effect on the wealth of either their families or their communities.

It struck me as something closer to credit cards for all instead of business loans for all. When you're poor, credit can help carry you through periods where you might lose a lot due to unlucky circumstances, but it will not actually increase your productivity or efficiency. Repayment rate has nothing to do with long-term social impact.