"but how others choose or are able to feed their children really is none of your business"
This thread is a general discussion about feeding choices. Nobody has made any personal judgement on any individual's choice, neither do they have the right to.
But babies' sole source of nutrition for the first six months of life is a public health issue, and it's wrong to suggest it's an inappropriate topic for debate.
As for the disadvantaged children you describe, nobody here is saying that it's more important for a baby to be breastfed than to be loved and cared for, but actually babies bought home from hospital into the most chaotic, dirty and disorganised households have by far the most to gain from being breastfed, as long as their mothers aren't currently abusing alcohol or drugs.
Those are the babies who are far more likely to end up in hospital with gastric illnesses from unhygenic bottlefeeding, the more likely to be abused if minor infections make them more fractious and harder to care for, for a parent who is already barely coping.
Really disadvantaged children often get the worst of everything in terms of education, nutrition, housing. A few months of breastfeeding would give them a nutritional start in life as good as the very richest baby in the country. Why shouldn't we want this for them? It might be the only time in their life they ever get the best of something. 