I don't believe the road rage argument.

If any of you have been in China traffic, people cutting you off can be measured in incidents per second. Horns are used like blinkers, and blinkers never seem to be used. You get used to it.

There's also huge amounts of pedestrian, bicycle, electric bicycle, scooter, tricycle, and motorized whatchamacallit traffic weaving all over the place, since not everyone can afford a car (or is even licensed properly). It's total chaos sometimes, you're expected to be careful, and take the odd bump in stride.

The guy that carried out the murder was shamed publicly and he would face a lifetime of ostracism. No one would want to associate with him for fear of being tainted in image, kind of like being friends with a known sex offender. Death is probably the most merciful decision.