Can I ask what makes you think this? The paper this article references is a study on measuring poverty in the developing world. To quote the authors it uses "survey and satellite data from five African countries—Nigeria,Tanzania, Uganda, Malawi, and Rwanda".

Here's a quote from the paper in question. Sure, we know where impoverished people are in a general sense. What we lack is the data required for effective decisions regarding aid and developmental assistance.

Although the quantity and quality of economic data available in developing countries have improved in recent years, data on key measures of economic development are still lacking for much of the developing world. This data gap is hampering efforts to identify and understand variation in these outcomes and to target intervention effectively to areas of greatest need.

Gathering sufficient data to make such large decisions isn't only difficult in the developing world either. Here in New Zealand we were due to hold our nation wide census on 8th March 2011 though due to the Christchurch earthquake on 22 February 2011, it was cancelled. The earthquake caused an estimated $40 billion NZD worth of damage, approximately 29% of our GDP. The census was eventually rescheduled and held on 5 March 2013. Our Government heavily relies on census data in it's funding forecast models. The two year census data gap introduced significant errors in some models, compounded by significant population and economic changes caused by the earthquake. As a result a number of Government services were incorrectly funded. Over 5 years later and we're still seeing after effects of this data disruption, particularly around the area of mental health funding in the earth quake effected regions. With this in mind, it shouldn't seem so far fetched that satellite imagery will prove a useful tool in accurate poverty mapping.