We can put 2 and 2 together and figure out that physical isolation in environment where people live far apart from each other and drive everywhere is... isolating?

And by the way, there are studies that show that even for introverts, socialization (even forced!) is ultimately good.

We're not made to sit alone in a room in the middle of nowhere. We were born in caves filled with our tribesfolk, dozens and dozens of people living together in small spaces.

Also, who said anything about alcoholics? Alcohol is just bad for you. Anything except for very small amounts has a ton of bad side effects. It's just "grandfathered in" (just like tobacco) and seen as socially acceptable.