Earlier quoted context omitted.
Of course cars have a place too. Having two smallish children, cars are a great way for my family to get around for many things. But it's nice when they are one option among many, and not set on a pedestal as the only one. For instance, when we lived in Padova: we'd ride bikes around the neighborhood when the weather was good. I'd walk to get groceries. My wife and I often rode bikes downtown for 'date night'. We'd t…
Changing the way cars function inside the city is only part of what would need to change. Near me things just aren't laid out well for pedestrians. It would take me about an hour to walk to the nearest grocery store (not counting corner stores, because all they sell is junk food). Biking should be much shorter, though I can't say I've ever tried. We would need to stop the trend of having a small number of large store…
Your statement is only true for low speed roads. At higher speeds, it is impossible or unsafe for anyone to use the road unless they are also going at an equally high speed.
So in practice, cars do NOT function as a lowest common denominator, but actively drive out other means of transportation because the roads they prefer -- high speed roads -- cannot be safely used by pedestrians or cyclists!