There is one pokestop that my kids can walk to from my house and it is a 15 minute walk. There are no other pokestops that are walkable in a 10 mile radius. They are too far apart and many do not have continuous sidewalks leading up to them, even if we wanted to walk that far (which would take us an hour round trip to get two additional stops). I dont have time to drive from stop to stop and turn into each parking lot and park so that my kids can get the pokestops. The like to walk the neighborhood to find the Pokémon so the exercise part was still accomplished. We dont live in the middle of a large city where there is a pokestop every 10 feet. If my kids were adults and worked downtown, we would have no issues. We pass about 5 pokestops, on a good day, when driving around and that allowed my kids to be able to keep playing...until the speed block was added. They tried to play for a bit after that, but could never keep enough poke balls in stock to make it any fun. They dont play anymore at all! Way to ruin a good thing!
Roamsai about Pokémon GO, v1.29.1