Safety.<quoted text>China indeed has purchased speed trains from both Siemens and Japan. But both countries were willing to sell China only the older models, but refused to sell the newest technology.
First Japan's allegation that China stole its technology was groundless because the China speed trains system which is so popular within China now is called Dong Che system but not magnetic system.
How come China's speed trains now run much faster up to 380 km/hr practically, and theoretically in experiment up to 500+ km. Japan and Siemens trains are much slower in applied speed. Is that a result of research and innovation within China because Germany and Japan cannot give China the technology. Is the new Chinese technology from God?
That's why China has faster train services.
Japan has almost 50 years of high speed train operation. In that time there has been only one derailment and that was during an earthquake.
In comparison China has 6 years of high speed train operation. In that time there were 2 derailments with 40 reported deaths and instead of having a public enquiry to increase safety, the chinese government tried to cover it up.
So it isn't that Chinese trains are better, it's just the Japanese government care a lot more about their people.