Ok, apparently for this situation to be livable you not only have to be healthy AND the weather has to be good (you don't go on a walk with kids every day when it's 100 degrees out or when it's blizzard of rain), you also have to have plenty of time for daily walks :)

Again, my point is, for most people, in most circumstances, 1km is a borderline unreasonable walk, and 2km is absolutely unreasonable and not "walkable" in any way. Sure, for some people in very special circumstances (and climates, or times of year) it might work out, but that is not a good basis for policy.

Also frankly it's just an inferior quality of life when your walk is to the grocery store thru dense burbs... I happen to have 2 large-ish parks nearby so I walk there, but not every day and in any case neither is on the way to any grocery store. I would never just walk around the neighborhood - instead, if both were 1km away, I'd drive to a park or a hike if I had to... then drive to a grocery store.