When I was in Taiwan in '95, this was the SOP when a light turned green. Everyone would rush into the intersection to see who would get there first, and two or three cars would make left turns before the through traffic could assert itself. This did not cuase any road rage, as it was expected behavior. I saw it for the first time today in Orange County CA. It was only one car, of course, as this is not the cultural norm here. I do expect to see more of it. One thing that is very common in LA for the last fifteen years at least is for a car to get into the right turn lane, then race across the intersection when the light changed, cutting off the car in the right through lane.
I expect to see more of the behavior the OP described going into the future. Hate it all you want, I intend to prepare for it and add it to my list of defensive riding tools.