Even then, 15 minutes is quite a radius. I wouldn't want to be a 3-minute walk away, but a 15 minute walk is like ~8 blocks.
Granted, that probably necessitates other homes being a lot closer than 8 blocks, so I suppose this just becomes a micro-scale NIMBY-ism. So I suppose you're probably right.
That said, there are lots of places where you have massive grocery stores at the ground level or underground in high-density urban environments, so you can get massive scale with high walkability, if you're willing to move past single-family homes (which we must... I say despite wanting a single-family home for my family.)