> Am I wrong to use when this issue started as the discussion starting point?
You're wrong about when it started. It's a lot more recent than that. We didn't build this way in 1904; we couldn't have afforded to live like this because we didn't have cars. A lot of places in the US were actually bulldozed since then to replace them with streets and parking.
American zoning specifically was introduced in California for the sole reason of keeping Chinese immigrants out of white neighborhoods - the idea was that if you banned running a business out of your home, they wouldn't be able to afford the neighborhood. (See "The Color of Law"… or you can read the city council minutes because, like, that's why they said they did it.)
But it's been kept since then mainly because of the assumption that everyone will own a car; cars cause traffic, so you can't attract them or strangers will make noise and park in front of your house.
Funny enough, another reason it's been kept in California is that 70s environmentalists read "Urban Growth Engines" and "The Population Bomb" and decided it was good because more expensive housing would stop people from having children. This is probably the inspiration for that Thanos guy.
> If you were to drive (because they aren't designed for walking) along the 'Walmart strip' of any town in the USA I can't see how you can argue 'the USA has too strong of city planning'.
Those are entirely caused by city planning. For one thing, no developer would want to build this way because it's not profitable - all that concrete for surface parking spaces is super expensive and nobody is using it. Parking minimums, stroads, federal highway funding, height limits and NIMBYs all come together to create sprawl. (See "Strong Towns".)
Oh, and fear that denser housing would lead to everyone dying in a nuclear war, that too.