We used to have a much more rigid system of social enforcement - for good and for bad. People used to feel bad when they did things society disliked. It had real consequences. People knew what you did and you wouldn't be invited to events or be hired. The downside was that people who lived alternative lifestyles (such as those who were gay) were also ostracised.

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.

Isolating yourself in certain situations isn't the same as not having human interaction and sticking 10 million humans in a small area and expecting them to always interact with all of the others is in no way normal or natural. Sometimes interacting with ~100ish people (within an order of magnitude) over your month is natural. Too many is both exhausting and diluting of the meaning, too few is lonely and over isolating.

You're trying to follow an out-of-date map. Our technology-infused growth of the past 50 years has produced more widespread mental illness and psycopathy than someone in the 80's could have even imagined. At this point in our societal evolution, you cannot assume that HUMANS THEMSELVES are either normal or natural.

Human interaction, sure. Human interaction with complete strangers, 10 inches away from you, enclosed in a metal tube you cannot escape from easily... not so much.