The argument isn't "Instagram is publishing people's locations," it's "People are allowing lots of services, Instagram among them, to publish their location, and it's harder to participate in modern society while reliably opting out of all of them."

It used to be the case that you could call up the phone company and say, please leave me out of the phone book. It still is. But there are so many more ways to learn your address today, and as always with security, it only takes one oversight to be compromised.

There's nothing unique about what Instagram is doing. They're one of several services other than the phone company that can leak your location if you're not being constantly vigilant. They're not notable, and that's the real story.