Yes, Granite Bay is a great place to keep your sports car collection, but places in Sacramento where you can walk and bike command a premium compared similar places without the same walkability.
But you are moving the goal posts here. The person I responded to didn't say compared to similar places without the same walkability. They said "the fact that America's most walkable and transit-accessible neighborhoods are also the most expensive and highest demand". Granite bay shows this to not be a fact.