Does anyone else hate how superior feeding mothers think they are to formula feeding ones?

Seriously! My sister has recently given birth to a beautiful baby girl and has decided to formula feed her instead of feeding, due to a few reasons. But whenever she reveals this to other moms and on new mom forums, she immediately gets attacked over how selfish and thoughtless she is to do this and how the baby will be unhappy and unhealthy and that formula feeding will never measure up to feeding. I don't want to be rude or offend any mother who feeds by saying this (it is completely your own personal choice whether or not to bf) but I wish they'd stop being so horrible and just be supportive. Does anyone else feel this way?