On those very few occasions when I needed to nurse an infant in public place , I at least tossed a soft flannel baby blanket over my shoulder and the baby's head . There is no reason you can't be discrete , and a bit modist . Can't say I feel good about women who have completed nursing their little one , who then sit there fully exposed in a deep conversation with others while hanging out with no baby attached . Just my opinion , not a law or rule .

Whut?

Maybe you mean why the lack of indifference to publicly nursing women?

In theory a woman can be as [im]modest and culturally [in]appropriate as she wants to be. In practice, she should not whimper about people having malfunctions with it though. Maybe it's not a hill to choose to die on. Maybe it is. That's up to nursing women to sort out for themselves.

Personally I'll stop being disgusted by public semi-nudity on the day I can take a piss in public anywhere and anytime I want to. And when people don't get arrested for masturbating in public, or walking about forgetting to have put their clothes on.

I've never had a problem with women nursing when / where they need to without imposing it on others or drawing undue attention. Strategically placed baby blankets are wonderful things. That "I dare you to say something" glare when a woman whips out of their breast in a supermarket checkout lane (yeah, I've seen it) is another.