I live out in the countryside. If I run into someone in the road, I will nod my head, maybe introduce myself, and maybe chat, if the other person is interested. (To be fair, I know about 80% of the people I see in the road.) This is normal behavior. Sometimes, two cars will pass each other and stop to talk.
I have also lived in the city. If a stranger wants to talk to me in the city, either they're looking for directions (happy to help!), or they are deeply confused about appropriate social behavior in crowded spaces. In the latter case, I'm lucky if the stranger-with-no-boundaries merely wants to warn me about the dangers of the lizard people. So I've learned to ignore strangers.
A neat summary of the article.
Talk to the old fogies in said city and they will saddle you with complaints of how people used to say good morning, how are you doing, etc. It didn’t used to be this way. Alas, we probably won’t be talking to the old fogies either.
Unfortunately we threw the baby out with the bathwater, and decided that all actions are equally socially acceptable and there should be no social repercussions for living "differently."
This is why I prefer smaller, culturally homogenous communities. We all understand the rules and we generally abide.
I feel like this has almost never been true in big cities: it's impossible to know everyone and unless they made the news for what they did word wouldn't travel very far.
Besides that, I also haven't observed what you're describing in both the smaller communities and the cities I've lived in. People absolutely do still get socially ostracized all the time in real life.
Thinking so is immature and unwise behavior.
Some people are comfortable with that, some people (say they) are used to it, but a lot of people find that blocking it out works better for them.
I don’t think you can say this categorically without taking context and a myriad of facets of one’s socio-emotional situation into consideration.