These are towns that were founded in the 1800s at the latest and some in the 1600s...
From my understanding Strong Towns think "lower density, less intensely urban development" towns are fine. E.g. at 0:57 of the video, it's anything but intensely urban development.
"In this example, a 100-year-old commercial block, built in the traditional style of development, drastically outperformed a shiny new development, created in the modern car-centric style."
But then I look at the housing prices. TimPC's explanation seems legit.