missratty , not sure what you mean. If people state that until formula came along, there was no alternative but to breastfeed, how does that 'make formula feeders feel bad'?
In fact as the article points out there is evidence that there have been alternatives to breastfeeding in many cultures, though for most of human existence, breastfeeding was universally the norm.
Other methods were sometimes unsafe and even wet nursing was unsafe for many babies - babies in eighteenth and nineteenth century France and Germany were often sent to baby farms where they were starved. It's not the case that women only ever used alternatives when they physically couldn't breastfeed either. Social strictures on upper class women in some societies prevented breastfeeding. This led to the serial pregnancies, miscarriages and stillbirths of eighteenth and nineteenth century royalty.