I would argue that this approximately true for adults, American cities don't have pedestrian-only town squares, the public transit is abysmal (because long ago they ripped out all the streetcars, which led to the destruction of many social places, like Excelsior Amusement Park and Wonderland Amusement Park),
[warning anecdotal evidence]
The few dynamic social spaces I've known have been
Paved (Hidden Beach),
Pushed out due to rent increases (Loring Bar, Little Nikkis Cafe, CyberX),
Turned into a Bank of America (Filter in Wicker Park),
Out of business due to the smoking ban (The tobacco shop next to Filter in Wicker Park)
Purposefully destroyed by fake art to prevent gatherings (That little area next to the Subway on State Street in Madison, WI (where I used to play hackeysack))
Not to mention that we destroyed all the beer gardens during WW2 (this really happened), because that was too German, you can't drink a bottle of wine in a park like the French do, because I guess the drunks would abuse it, and the parks we do have generally don't also have any commercial activity whatsoever, not even a little kiosk where you can buy a coffee.
That's not even considering the destruction of ethnic neighborhoods by intersecting them with freeways (the old Catholic neighborhood [that no longer exists] that used to surround the Basilica in Minneapolis)
You know we're doing something wrong with urban design (which I argue is directly related to loneliness), when you see statues of children playing and not actual children playing.
Further reading/viewing:
James Howard Kunstler: The ghastly tragedy of the suburbs
James Howard Kunstler: Geography of Nowhere
The Slaughter of Cities: Urban Renewal as Ethnic Cleansing
Streets for People: A Primer for Americans
Bowling Alone: The Collapse and Revival of American Community
The Great Good Place: Cafes, Coffee Shops, Bookstores, Bars, Hair Salons, and Other Hangouts at the Heart of a Community