How did they know how to build this? It’s simple. They just copied what they knew worked.
We like our places to emerge fully formed and then we expect them to never change, but that's not how life works. Cities are like living things. They need to be able to change and adapt, to start small and mature incrementally over time.
We can't wait around for a big developer or a mega-project to fix our cities. The kind of development we need today happens at the scale of a Strong Citizen, someone who cares about the place they live.