Why is this a reckless driving question and not a reckless pedestrian question?
Extremely valuable places have lots of people interacting. Low value-per-acre places accommodate cars well. When there is a conflict between the two, the higher value-per-acre use should be expected to win because, by the mechanism that we use to allocate the space (money), the higher value use is, by definition, better.
Also, from a perspective of what was there first (another principle of ownership): unarmored, walking people are the default state of humans. Armored 4-ton 65mph people are a recent change and a very expensive change, at that. So it stands to reason that we prefer the pre-existing state (though not by the US American traffic engineering system.)
There is also an ethical principle deriving from Judaism, and expanded by Christianity, which says that all people have intrinsic value and by extension should not be killed. This intrinsic value is accepted in western culture and is taken to apply to all people, whether they are too disabled to drive a car, too young to drive, too old to drive, or too poor to drive.
I know this is just a small sampling of the answer to your question, but I don't want to get too tedious here.