> ... people regularly commute to Tokyo from all over Japan.
I feel like this is one of those things that sounds like it might be true, but isn't. It's four hours from Tokyo to Hokkaido by train, f.e., and not much cheaper than a flight.
> I know that is difficult to imagine in the US, but please have an open mind.
I do try to have an open mind, despite being an Australian living in Australia.
My work requires that I travel regularly - most major cities in Australia warrant air-travel, due to the distances involved, but price and (in)convenience of air travel reduce the appeal.
Sydney to Canberra is a curious exception - at around 300km it's actually slightly faster to drive than to fly, once you factor in intra-city commute (to / from airports) and usual security & check-in waits. I'd love a high-speed ground-based option, as short-haul flights offend my green sensibilities, and as much as I enjoy driving, I can get more done, have a safer journey, and be more relaxed if I'm not driving. There is a train service - but it's not terribly frequent, and takes more than 4 hours (plus the intra-city commute, as for air travel). There's been talk of high speed rail links along the east coast (Sydney, Canberra, Melbourne) for decades, but still no actual commitment in sight.
I'm highly envious of what's happening in other parts of the world.