Where's your citations for your statements? You can't go making up facts without backing them up.
Bullet trains travel on a track, they do not travel freely with other bullet trains in crowded roadways. Pretty much anyone with a pulse can get a driver's licence and many people don't take driving seriously as "I am putting my life and other's at risk when I step into my car." Most people don't own a bullet train. The comparison is useless.
Plus speeding trains do kill when they go past the posted speed limit, which is posted for safety reasons, example:
http://www.nytimes.com/2013/12/03/nyregion/metro-north-train... - by the way that train crashed on a Sunday, if it was a weekday there would have been hundreds dead as it is a major commuter line. Instead there was only 4 dead.
Here's some research that says speeding contributes to crashes. However, a car travelling much faster than the rest of the cars on the road are the most dangerous.
http://www.sciencedirect.com/science/article/pii/S0001457598...
http://trid.trb.org/view.aspx?id=712279
http://www.nsc.org/safety_road/DriverSafety/Pages/Speeding.a...
http://www.sciencedirect.com/science/article/pii/S0001457505...
We have a problem when people post random speed limits without actually studying and taking into consideration safety.
Bullet trains are designed to go fast safely. When the parent talked about speeding they were talking about going past the posted speed limit, which for argument we will assume was posted for safety considerations. Of course, the faster one is travelling if there is an accident, the more deadly the accident becomes. This is simple physics. Bullet trains also have a speed limit, just a much higher one, and I don't know if they are physically built to travel past the safe max speed.