I never had people complain about breastfeeding in public.
Did get some remarks from a woman about how delighted she was that I did not mind feeding a kid during a church wedding service.
But as Parts said, breastfeeding most of the times is done pretty discrete. There is no need to flaunt tits in public, and, while breastfeeding, you do not want your boobs go cold either. You don't want to risk mastitis, that hurts like hell.