Walkability isn't a binary thing I guess. I'm in a pleasant but unexciting town (population 12K) in the UK and everybody is in walking distance of the schools, the supermarket, parks and leisure centre. Most houses here are 3 or 4 bedroom (but probably small compared to US family houses and gardens aren't huge), but you do really need to drive to say get to many types of shops, a cinema or any restaurant that isn't an Indian or Chinese for example. I get the impression that most people drive to work (most jobs are in larger towns nearby, some come be reached by train but not all). I suppose there is a balance between house prices, space and the level of walkability and like many families here, this is the compromise we've gone for.