Phoenix is uninhabitable precisely because it's entirely optimized for car life from what I heard? (i.e. massively spread out, no walkability, etc)
I suspect they were mostly referring to it being uninhabitable due to the extreme heat and duration of 100ºF+ days.
It's car optimized because the 110F weather makes it un-walkable in the first place. When I lived in a walkable city, I would prefer to walk 30 minutes than drive. When I lived in Phoenix, I did not want to spend more than 30 seconds outside in the summer.