I think it has some to do with generations, but also a lot to do with what we're used to as a society. Take me for eg: my family were only ever breastfeeders, as were dh's family. There was no formula feeding from any of them. They're very open about it, so that's what I'm used to. When I was pg with DD1 and even after I'd had her and was learning to breastfeed, I had a wealth of experience from both families helping me, so for me it was an easy decision to not only breastfeed, but to also do it with confidence in public.
However, my BIL's DW is from a family where breastfeeding is not talked about. Most of the babies were formula fed, and that's all she knows. She does not plan on breastfeeding her baby-to-be for two reasons. She doesn't understand the benefits, and she's embarrased.
I'm Gen Y, she's Gen X.

Breastfeeding vs Formula feeding is a huge debate. Always will be. There are many people out there who look down on women who formula feed. I think that is where msadelaide is coming from. That because so many people look down on those formula feeding, she may have thought she was being looked down on.