Fortunately, the serious advocates for more walkable cities aren't calling for absolutely everything to be within walking distance, only the most commonly accessed things.

Where do you go in a typical day or week or month? Groceries, restaurants, gyms, entertainment, maybe the doctor/dentist?

Trouble is, if there is somewhere you need to go that is so unique that a dense city population cannot support it locally, within walking distance, you also won't have the ridership necessary to support transit to that destination. Just you sitting on the train doesn't work – even the original comment said that cars are necessary in such cases. Mass transit requires mass ridership.

Our "solution" to that problem is to make cities wannabe rural areas, where the services are many kilometres away from where the people live, requiring a trip by car/train/bus/whatever just to do anything. Then you have some guarantee of mass ridership. But having to get into a vehicle to do anything is a horrible way to live. It's the worst part of living rurally with none of the upside of living rurally. If you are going to live in a city, why not embrace it? I get having a large rural acreage is everyone's ultimate dream, but maybe it is time to accept it is not in the cards and start to love the one you're with?