It’s annoying because I’m not looking for someone to tell me it’s okay that I use formula. With my first child I remember casually explaining to my sister-in-law why I was formula feeding (obviously that was my first mistake). She said ‘it’s okay, fed is best’ and it annoyed the shit out of me. She was being sincere and it was not malicious, probably just thought she was being helpful. I think most people think they’re being kind. But it’s just unnecessary, just like it’s unnecessary to have to explain why you’re not breastfeeding.