I live in a 3rd world country, and honestly, people seem to concentrate way too much about "dirty" water being the culprit. Most of our people has access to clean drinking water. And clinics showing them how to mix formula. Not all third world countries live on dirty water and no education (on formula).
The thing in our country is that the infant mortality rate is way higher than it should be, and part of it has been blamed on mothers choosing to formula feed rather than breastfeed (because formula was made out to be as good as breastfeeding). It's just a fact that when you have 1000 new mothers who uses formula, and you compare it to a 1000 new mothers who breastfeed, that a bigger percentage of those babies that got formula will be admitted to hospital for diseases during their first 5 years of life, and more of them will die. So in a drive to get our infant mortality rate down, breastfeeding is promoted and encouraged much more the past 5 years. They even went as far as stopping the practice of giving formula at clinics without a prescription from a peadiatrician.