Yeah, I don't understand why anyone would continue to look at a woman who is breastfeeding if it offends you. There are a million other things to look at. And as previously stated , the window for seeing anything offensive (or salacious) is quite small so unless you are laying in wait for something to happen, you are probably not going to see anything other than the back of a baby's head. And if a woman does cover up, a wiggling or thrashing baby might expose the mother . I guess if you really want to know what God thinks about it then search the Bible for what God does say about breastfeeding and what the verses about modesty actually pertain to and speak to a pastor. Babies don't care where you are, if they are hungry they need to eat. Waiting until you get home is neglect, staying at home all the time is not feasible, going into a bathroom is gross and not healthy for the baby, and even the most well meaning covering up can go a different way so I guess babies are co partners in exhibitionism. God created women to be able to feed a child literally anywhere and it's not a sexual thing.
Personally, I don't know where you are seeing women totally topless feeding children; all my experiences as a nursing mom and as a friend to other nursing moms has been women do try to wear covers or special clothing that covers things or makes things easier and comfortable for mom and baby without feeling exposed; and people will still say ignorant things even if no one saw anything remotely private. Even women that don't have covers are hardly out there exposing their breasts to everyone around them. If it's happened once to you , then it's probably out of the ordinary and doesn't mean that all breastfeeding mothers should not feed their babies when they are out in public.