All sorts of reasons.
Several years ago in Houston, we (there were several of us) drove across the street to have lunch most days. Over the course of a year, I never walked the route. Line of sight was maybe 500 yards, but a busy freeway was between the restaurant and our office. While you might think I'm crazy, I don't recall ever seeing any other business-dressed people walk under that freeway. you would be soaking wet from the heat & humidity by the time you got to lunch.
I think Minneapolis figured this out the best with a downtown connected by skybridges on the 2nd floor connecting tons (most?) of the buildings).
Yeah, and? Most people also find pickup trucks excessive. And yet, they are the most profitable vehicles on the planet. So much so that Tesla wants to make one. There's a whole world outside the urban bubble, for better or worse.