i like cider:I know that breastfeediong mothers can express milk and put it in a bottle, and I am sorry but I think that on certain occasions this should be done.
I'm a very proud breastfeeding mum and whilst I can express, my daughter simply refuses point blank to take any milk (either expressed or formula) from a bottle, cup or anything else that's not me, so it's not as simple as you make it sound. Have a heart and think of the way the mum feels - usually when her baby shows signs of being hungry, they are already attracting attention from other people, so the last thing she needs is to be 'tutted' at, asked to leave, or stared at etc etc when she manages to get her little one to have a feed.
My local cafe owner actually praised me for feeding my baby whilst I was at lunch the other day and thankfully I didn't have one disapproving glance or gesture (well, not that I saw anyway!). It's not as if we're trying to get people to look at us, so if it offends you, sorry, but my baby has to eat, and does eat, whereever she wants to!