I'm very pro-breastfeeding, but I do remember a 'friend' who was very, very fanatical - she basically defined it as the be-all and end-all of good parenting - saying that she thought that formula should be restricted by the government. As in, only available by prescription, for those tiny percentage of women who genuinely couldn't, medically, breastfeed.
Now that's a feminist issue! She was advocating government control over the use to which a female body is put. Can you imagine, having to go to a doctor, presumably undergo medical tests, to prove your need for formula?
It does swing both ways. Our society sexualises breasts, it doesn't provide facilities or support for breastfeeding, too many women are faced with a straight choice between career and attachment parenting, if we valued the work that breastfeeding women do as much as we value, say, the ability to shoot people there would be a huge change in the resources and knowledge available. Those of you who have said that not being able to breastfeed properly in public meant giving up your social lives, I think if we lived in a matriarchal society this would just be a non-issue.
On the other hand, breastfeeding is a deeply intimate, deeply physical experience that is only available to women, and it does largely define the mothering experience. I weaned DD at around 15 months, not from any external pressure nor sense that she was too old or weirdness about sexuality, but because it simply, at that stage, wasn't something I wanted to do anymore. My relationship with her had changed, and breastfeeding her didn't feel very compatible with that any more. I was absolutely over, OVER, having my body made available to be suckled at. And this was after a nice, close, easy breastfeeding relationship with loads of social support. It was very visceral to me: I did not want to do it anymore.
And if another woman makes that choice earlier, I can't stand in her way anymore than I'll ever advocate taking reproductive choice away.