Most formula feeders don't give their babies formula for pure convenience or because we think it's best. We do it because we have no other choice!
I agree. I had a friend who is of the belief that everyone had a hard time and you just need to perservere. That's fine but at what cost? I had severe PND, attachment issues, a baby that never slept and screamed all night, mastitis and such damaged nipples. Was I supposed to have a complete nervous breakdown? She still makes snide remarks about it as she was able to breastfeed her bub past 12 months. I just ignore her as I know in our case I did what was the only thing I could. Mind you if she keeps it up I just won't have anything to do with her.

As for people in public, I was in a feeding room once and everyone was breastfeeding with their friends/mums/sisters with them. All those not feeding were also sitting and not one gave me their chair and I had to stand feeding a screaming 6 week old. That is the only time I thought I was being punished for FF but we survived. I never look around when I am out and about feeding him, I am too busy watching how he is going and talking to him.

Don't worry about them or just tell them to take a long walk off a short pier. You are doing a great job and people should just mind their own business.