Guilt (deserved or entirely undeserved) comes from within. The emotion is horrible and painful but seeks a scapegoat. The gauche actions of a group of breastfeeders, or the tactless words of a relative or stranger, or the rushed behaviour of a midwife are an easy place to hang that guilt.
Breastfeeders are people as well! They are as self absorbed as the next person. I'm sure they are not trying to foster guilt. You do a fabulous job of that yourself. Nothing anyone says about formula being 'just as good' or hiding anything positive about breastfeeding will change that.
Guilt is incredibly complex and often doesn't have just one source. The whole bf/ff argy bargy is riven with other wider issues about parenting styles.
I'm only saying this as I know a bit about guilt. I felt extreme guilt that I was partly responsible for my father's suicide. Now, none of you would say I was responsible, would you. Rationally I know I'm not responsible, but I feel it like a lodestone around my neck.
This is all my own work and nothing anyone said, did, or didn't say affected it.
You cannot, simply cannot make a person feel guilty if they don't feel guilty. But you can't change the facts of life so that guilt isn't an issue.
Again, this is all part of the whole 'everyone wants you to breastfeed, but not next to you, or while you're eating, OR for you to talk about it'
Try NOT talking about, or getting enthusiastic about something you've spent 18 hours a day doing for months and months.