ISNT, you're missing the point. Those women that cannot bfeed for medical reasons or failed to bfeed due to poor support, the ones that you refer to as feeling inadequate and guilty, they aren't the ones that the posters are aimed at. You say the campaign isn't hitting the spot, but they're trying to encourage people to feed, to normalise it, they're not comments on those that didn't or couldn't.
How far do you want to take this? Posters about best practice for avoiding SIDS. They are aimed at the women making the decisions now, if they make a woman who sadly lost her child to SIDS feel guilty for co-sleeping for example instead of using a cot, do we say the campaign isn't working? No we don't, we say that the woman's experience means that she brings a lot of emotion to the reading of a poster that others don't but it doesn't undo the veracity of the message or its importance.
I feel guilty and inadequate daily that I couldn't have a natural birth. Am I arrogant enough to assume that they should stop promoting the idea that a natural intervention-free delivery is best? Of course not. I'm more passionate about it, despite the guilt and feelings of inadequacy. I don't want to hide the message away, I want other women supported to not feel the way I do through encouragement, information and promotion and support for those few for whom the 'best' isn't attainable.
The poster further up who said 'breastfeeding is normal, am I ABNORMAL?' shows the problem. Breastfeeding is normal and needs to be normalised further in this country. No it's not a comment on you or an implication. FF is inferior. It is artificial. It might be the norm in this country, it might be an adequate substitute but it's not 'normal' by definition.