From interviewing a woman who has breastfed her 3 children in the present tense, results have shown she was most comfortable feeding her babies in a private area such as in the comfort of her own home with people she knew would not take offense for example family, close friends. However, it was inappropriate to breastfeed her babies in a public place as she was more self consciousness about herself and making others around her uncomfortable which made it seem inappropriate.
With this in mind other Mums feel this strongly about their own choices and simply because they differ it does mean they are wrong. Every mother and baby is different and unless you know them intimately you cannot judge their individual situation.
Historically breastfeeding was not accepted in public due to the concern of some people seeing a woman's bare breast in public as she takes it out to feed her baby. This may be unexpected and even offensive to some, but the fact is that breastfeeding in public is typically legal, and babies need to eat often.