The reality is, people want walk-able neighborhoods. In fact, the places where they exists, they are so horrendously expensive that people can't afford to live there. There are so few of those places that the demand/supply is just crazy. So even if there was a good walk-able neighborhood most people couldn't afford it.

The Texas DoT isn't about transportation, its basically about highway building (and often right threw neighborhoods). 60 years of infrastructure investment in on thing lead to more of that thing.

There are about 160 car accidents a day in Houston alone. The amount of cost society gets from that is huge.

Population count is just one of many metrics when evaluating the "niceness" of a place. Maybe "destroyed" is not the best way of describing the effect of car dependency (my english is not that good) but a city that doesn't value walking sounds like hell to me.