Personally, I have been very disappointed in maternity clothes since getting pregnant. They are tight and are made to show off the 'bump.' I don't really understand why pregnant women would want to dress like that. I have some maternity clothes, but for the most part I have been wearing regular tee shirts with maternity jeans or sweats. I just want to be comfortable (not to mention I feel like a huge elephant ;) ). If someone wants to flaunt it all like that that's their choice, but certainly not mine. Then again, I was never one to wear short skirts and tiny little shirts, even when I was thin and would have actually looked good in them. It's just not me.
I also have no problem with breastfeeding done in public. It's much healthier for the baby. However, I do believe it can be done modestly.