We could argue that modern town planning is in fact infected with a Sim City spirit (or Sim City captured that existing spirit): artificial separation between "commercial" and "residential areas" with miles and miles of separation between them, and car-centric in the extreme.
The Sim City world is one where you have to ask permission for everything. Development is prohibited by law unless the benevolent town planner opens up an area with little colored rectangles. But you can only build one type of building and can't mix & match because the top-down view of the planner blurs out the complexity at the ground level.
Sim City does have a redeeming feature, favoring urban density. Traditional planning is more aligned with creating loose, low-density, detached abodes, with great separation and height restriction and far away from any semblance of economic activity: shops, factories and commercial space.
Having to support an infrastructure (necessarily a car infrastructure) in these forms is tremendously inefficient and can be considered as a great cost on societies that found out about planning before most cities got established (early 20th century).
The 'modern town planning' you talk about is so called Euclidan zoning (named so from the town of Euclid in US where it was supposedly first introduced - as a way to segregate rich from poor in an indirect way). Not all areas/countries use such laws. Some time ago this link hit the front page of HN: http://urbankchoze.blogspot.com/2014/04/japanese-zoning.html - it is really an interesting read (other articels on the site as well)
If you're interested in the history of this sort of thing Lewis Mumford's 'The City In History' is a fantastic read. Brilliantly researched and presented in a very non-dry way.
It's long been hip to blame SimCity for creating bad urban design. However: SimCity reflects ideas as much as it plants ideas: zoning existed before SimCity. SimCity promoted intermingled Commercial and Residential zones (traffic was lighter if they were nearer) with pollutant Industrial zones far away from the rest, and SimCity highly promoted mass transit over cars.
Most SimCity games indirectly went against mass transit, or at least the idea of building it up in phases, based on its traffic model.
A Sim's route was defined as a path from point A to point B, and a maximum time. If the maximum time was reached, the route was a failure and would reflect as increased congestion. If a Sim encountered mass transit along its route, it would attempt to take it using the same pathing algorithm as car travel. However, if the route failed while using mass transit, it would never try it again, even as mass transit service expanded and new bus and subway lines/stations were added.
The most recent SimCity was supposed to be more realistic in its route planning and simulation by giving each Sim a home, a workplace, etc., and repeating routes on a daily basis instead of a random sampling of routes, but this didn't make it into the final game.
From what I understand, haven't read up on it in a while though, they even went with a random sampling of housing for each Sim as well. The house they stayed in last night may not be the house the stay at tonight.
The Sim City world is one where you have to ask permission for everything. Development is prohibited by law unless the benevolent town planner opens up an area with little colored rectangles. But you can only build one type of building and can't mix & match because the top-down view of the planner blurs out the complexity at the ground level.
Sim City does have a redeeming feature, favoring urban density. Traditional planning is more aligned with creating loose, low-density, detached abodes, with great separation and height restriction and far away from any semblance of economic activity: shops, factories and commercial space.
Having to support an infrastructure (necessarily a car infrastructure) in these forms is tremendously inefficient and can be considered as a great cost on societies that found out about planning before most cities got established (early 20th century).