Both. And with different constraints at different time periods.
Aside, people in the past weren't stupid and they built cities purposefully. Just like cavemen weren't stupid, they just had less _stuff_, knowledge, tools, etc.
> In any case what value does this "norm" have?
Using less fuel. Enjoying a more healthy body and mind, enjoying life. Leaving a better world for its future inhabitants.
> You would prefer to walk around a city because it's that's dense as opposed to walking around nature that's specifically set aside for this type of enjoyment?
Strawman ("because it's that dense"). I like walking in cities AND nature. Both can be true.
Also, why should nature be "set aside"? What a weird notion. Why shouldn't we have more "nature" in our cities, in fact we know it's probably better to do exactly that, for a myriad of reasons that have been scientifically researched. Why should WE "set aside" nature, as if it was somehow external to us.