* People (especially those with children) often prefer to live in houses with space which are more private rather than in narrow apartments (required if you want low building heights and for everyone to walk everyhwere) on top of their neighbours. Do you really want to hear 3 screaming babies next door every night. Because that's how it works.
* Modern business don't work in low desnity environments like this. You simply need to be as accessible as you can to as wide a market (of workers and other businesses you work with) as possible. Maybe once we are all working on the internet it will shift this way - but it hasn't gone far yet.
* Even the 'traditional cities' shown will have outskirts with houses which are a pain to walk to rather than just apartments in a centre.
* There is no single 'traditional city'. There are differences even across Europe. England has its widened-road market squares. Italy has its hill towns. Places like Japan usually built out of timber (which doesn't last) rather than stone. Etc.
* There are plenty of examples of tower cities with bustling urban environments and low car ownership. Like Hong Kong. Dehumanising? Perhaps. It depends on your definition.
* Most 'traditional cities' couldn't be built for anywhere near the same cost as a modern development.
Overall though, this is pushing in the right direction, just not quite thought through as thoroughly as it might be.
[edit] Perhaps the most successful attempt at building in this vein in the west recently has been Poundbury, England. It was Prince Charles' pet project. It has done some things well (like managing to break the highways codes) but in the end perhaps still isn't as nice as a traditional town or as attractive a location for modern living as other places being built. You can see it in streetview here: https://www.google.com/maps/@50.712904,-2.463939,3a,75y,145....