Nick Wade in the NYT reports that a decent chunk of the sugars in breast milk are not digestible by the baby, but rather are there to provide a food source for a helpful bacterium and to act as decoys in the presence of harmful bacteria. Apparently no one had appreciated how much of mother's milk the baby could not digest, let alone what adaptive purpose this served.
Here again we see the wisdom of going with what hundreds of thousands of years of natural selection has designed, rather than with what man has. By preferring the short-term benefits of avoiding "all that hassle" associated with breastfeeding, and using infant formula instead -- it's close enough, right? -- she deprives the child of the long-term benefits of breast milk.
The harm done to themselves and others by this over-emphasis on immediate personal pleasure is why we need to apply more shame when someone acts like a wimp to avoid the slightest inconvenience. No hostile diatribe or casting out is needed, just frequent reminders from everyone in their social circle to "suck it up," "deal with it," "grow up," and "stop acting like a baby."