I think you have kind of made my point for me there ladyintheradiator. There are many many reasons that women don't BF, and to improve rates we need to find out the reasons and address them, no matter how off the wall they are.
If someone is pg and says they don't want to BF, and says the reason is they are worried about sex with their boyfriend afterwards if they are BF, to resond that that is not a reason and thus dismiss her concerns is not going to give the desired result.
To talk through her concern with her, with practical advice, might encourage her to give BF a go.
I would also contend that most of your friends are probably quite similar to you, which is why they tried to BF and when they stopped it was for reasons you consider to be valid.
There are, however, different sorts of people in the world, and some of them, believe it or not, will choose not to BF as they think it ruins their breasts.