I lived in China for 2 years. Americans have no idea how liberating it is to be able be able to hop on a 200 mph train and arrive at totally different climate in hours. Over lunch, my coworkers would talk about a weekend of drinking tea in mountains in Hunan, visiting Mao' home in Wuhan, or exploring the beaches of Hainan. These are all things we did and were possible because of China's high speed rail system.
I think the biggest factor was the convenience. We'd just show up at the train station and take the next train, usually within an hour. No planning, no booking, just bought our tickets at the station, minutes before our trip. All of this for less than 1/4 the cost of a last minute plane ticket.
Sure we could have flown, and the farthest places may have been faster to fly. But that only if the tickets were available and security lines in china are just as bad as here. There's also the comfort of a train with a meal coach. And, the thrill of watching the land rush by at lightning speeds. America felt so backwards on my return.